Sanitizer runtimes are currently behind the `-Z` flag, which is only available
on nightly builds of the compiler.  We would like to enable fuzzing on chrome
os anyway so move the sanitizer option under `-C` instead since we don't build
the toolchain in nightly mode.

The changes this patch makes are:
 - changing debugging_opts.sanitizer to cg.sanitizer.
 - add the appropriate options to options.rs.

diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs
index a4e17a5f675..0b109d392bf 100644
--- a/src/librustc_codegen_llvm/attributes.rs
+++ b/src/librustc_codegen_llvm/attributes.rs
@@ -46,7 +46,7 @@ fn inline(cx: &CodegenCx<'ll, '_>, val: &'ll Value, inline: InlineAttr) {
 /// Apply LLVM sanitize attributes.
 #[inline]
 pub fn sanitize(cx: &CodegenCx<'ll, '_>, codegen_fn_flags: CodegenFnAttrFlags, llfn: &'ll Value) {
-    if let Some(ref sanitizer) = cx.tcx.sess.opts.debugging_opts.sanitizer {
+    if let Some(ref sanitizer) = cx.tcx.sess.opts.cg.sanitizer {
         match *sanitizer {
             Sanitizer::Address => {
                 if !codegen_fn_flags.contains(CodegenFnAttrFlags::NO_SANITIZE_ADDRESS) {
@@ -123,7 +123,7 @@ fn set_probestack(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
     // Currently stack probes seem somewhat incompatible with the address
     // sanitizer and thread sanitizer. With asan we're already protected from
     // stack overflow anyway so we don't really need stack probes regardless.
-    match cx.sess().opts.debugging_opts.sanitizer {
+    match cx.sess().opts.cg.sanitizer {
         Some(Sanitizer::Address | Sanitizer::Thread) => return,
         _ => {}
     }
diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs
index dcce1d45298..ef5e7d2a42a 100644
--- a/src/librustc_codegen_ssa/back/link.rs
+++ b/src/librustc_codegen_ssa/back/link.rs
@@ -718,7 +718,7 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
 }
 
 fn link_sanitizer_runtime(sess: &Session, crate_type: CrateType, linker: &mut dyn Linker) {
-    let sanitizer = match &sess.opts.debugging_opts.sanitizer {
+    let sanitizer = match &sess.opts.cg.sanitizer {
         Some(s) => s,
         None => return,
     };
@@ -752,7 +752,11 @@ fn link_sanitizer_runtime(sess: &Session, crate_type: CrateType, linker: &mut dy
             linker.args(&["-Wl,-rpath", "-Xlinker", rpath]);
             linker.link_dylib(Symbol::intern(&libname));
         }
-        "x86_64-unknown-linux-gnu" | "x86_64-fuchsia" | "aarch64-fuchsia" => {
+        "x86_64-unknown-linux-gnu"
+        | "x86_64-fuchsia"
+        | "aarch64-fuchsia"
+        | "x86_64-cros-linux-gnu"
+        | "x86_64-pc-linux-gnu" => {
             let filename = format!("librustc{}_rt.{}.a", channel, name);
             let path = default_tlib.join(&filename);
             linker.link_whole_rlib(&path);
@@ -1509,7 +1513,7 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
 
     // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
     if sess.target.target.options.is_like_fuchsia && crate_type == CrateType::Executable {
-        let prefix = match sess.opts.debugging_opts.sanitizer {
+        let prefix = match sess.opts.cg.sanitizer {
             Some(Sanitizer::Address) => "asan/",
             _ => "",
         };
diff --git a/src/librustc_codegen_ssa/back/symbol_export.rs b/src/librustc_codegen_ssa/back/symbol_export.rs
index 970d13b30c0..50a82461fef 100644
--- a/src/librustc_codegen_ssa/back/symbol_export.rs
+++ b/src/librustc_codegen_ssa/back/symbol_export.rs
@@ -202,7 +202,7 @@ fn exported_symbols_provider_local(
         }));
     }
 
-    if let Some(Sanitizer::Memory) = tcx.sess.opts.debugging_opts.sanitizer {
+    if let Some(Sanitizer::Memory) = tcx.sess.opts.cg.sanitizer {
         // Similar to profiling, preserve weak msan symbol during LTO.
         const MSAN_WEAK_SYMBOLS: [&str; 2] = ["__msan_track_origins", "__msan_keep_going"];
 
diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs
index cb5c95c11fa..a040013901a 100644
--- a/src/librustc_codegen_ssa/back/write.rs
+++ b/src/librustc_codegen_ssa/back/write.rs
@@ -189,7 +189,7 @@ impl ModuleConfig {
             ),
             pgo_use: if_regular!(sess.opts.cg.profile_use.clone(), None),
 
-            sanitizer: if_regular!(sess.opts.debugging_opts.sanitizer.clone(), None),
+            sanitizer: if_regular!(sess.opts.cg.sanitizer.clone(), None),
             sanitizer_recover: if_regular!(
                 sess.opts.debugging_opts.sanitizer_recover.clone(),
                 vec![]
diff --git a/src/librustc_mir/transform/inline.rs b/src/librustc_mir/transform/inline.rs
index 35d55c4cb9b..e167ca3da51 100644
--- a/src/librustc_mir/transform/inline.rs
+++ b/src/librustc_mir/transform/inline.rs
@@ -232,7 +232,7 @@ impl Inliner<'tcx> {
 
         // Avoid inlining functions marked as no_sanitize if sanitizer is enabled,
         // since instrumentation might be enabled and performed on the caller.
-        match self.tcx.sess.opts.debugging_opts.sanitizer {
+        match self.tcx.sess.opts.cg.sanitizer {
             Some(Sanitizer::Address) => {
                 if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_SANITIZE_ADDRESS) {
                     return false;
diff --git a/src/librustc_session/config.rs b/src/librustc_session/config.rs
index 5bdd7b67723..41569753010 100644
--- a/src/librustc_session/config.rs
+++ b/src/librustc_session/config.rs
@@ -726,7 +726,7 @@ pub fn default_configuration(sess: &Session) -> CrateConfig {
             }
         }
     }
-    if let Some(s) = &sess.opts.debugging_opts.sanitizer {
+    if let Some(s) = &sess.opts.cg.sanitizer {
         let symbol = Symbol::intern(&s.to_string());
         ret.insert((sym::sanitize, Some(symbol)));
     }
diff --git a/src/librustc_session/options.rs b/src/librustc_session/options.rs
index a38e7f063d7..838fd26700f 100644
--- a/src/librustc_session/options.rs
+++ b/src/librustc_session/options.rs
@@ -759,6 +759,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
         "print remarks for these optimization passes (space separated, or \"all\")"),
     rpath: bool = (false, parse_bool, [UNTRACKED],
         "set rpath values in libs/exes (default: no)"),
+    sanitizer: Option<Sanitizer> = (None, parse_sanitizer, [TRACKED],
+        "use a sanitizer"),
     save_temps: bool = (false, parse_bool, [UNTRACKED],
         "save all temporary output files during compilation (default: no)"),
     soft_float: bool = (false, parse_bool, [TRACKED],
diff --git a/src/librustc_session/session.rs b/src/librustc_session/session.rs
index 048033846a1..b09e6acb981 100644
--- a/src/librustc_session/session.rs
+++ b/src/librustc_session/session.rs
@@ -650,7 +650,7 @@ impl Session {
             || self.opts.output_types.contains_key(&OutputType::Bitcode);
 
         // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
-        let more_names = match self.opts.debugging_opts.sanitizer {
+        let more_names = match self.opts.cg.sanitizer {
             Some(Sanitizer::Address) => true,
             Some(Sanitizer::Memory) => true,
             _ => more_names,
@@ -1017,7 +1017,7 @@ impl Session {
 
     /// Checks if LLVM lifetime markers should be emitted.
     pub fn emit_lifetime_markers(&self) -> bool {
-        match self.opts.debugging_opts.sanitizer {
+        match self.opts.cg.sanitizer {
             // AddressSanitizer uses lifetimes to detect use after scope bugs.
             // MemorySanitizer uses lifetimes to detect use of uninitialized stack variables.
             Some(Sanitizer::Address | Sanitizer::Memory) => true,
@@ -1354,18 +1354,32 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
     }
 
     // Sanitizers can only be used on some tested platforms.
-    if let Some(ref sanitizer) = sess.opts.debugging_opts.sanitizer {
+    if let Some(ref sanitizer) = sess.opts.cg.sanitizer {
         const ASAN_SUPPORTED_TARGETS: &[&str] = &[
             "x86_64-unknown-linux-gnu",
+            "x86_64-cros-linux-gnu",
+            "x86_64-pc-linux-gnu",
             "x86_64-apple-darwin",
             "x86_64-fuchsia",
             "aarch64-fuchsia",
         ];
-        const TSAN_SUPPORTED_TARGETS: &[&str] =
-            &["x86_64-unknown-linux-gnu", "x86_64-apple-darwin"];
-        const LSAN_SUPPORTED_TARGETS: &[&str] =
-            &["x86_64-unknown-linux-gnu", "x86_64-apple-darwin"];
-        const MSAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu"];
+        const TSAN_SUPPORTED_TARGETS: &[&str] = &[
+            "x86_64-unknown-linux-gnu",
+            "x86_64-cros-linux-gnu",
+            "x86_64-pc-linux-gnu",
+            "x86_64-apple-darwin",
+        ];
+        const LSAN_SUPPORTED_TARGETS: &[&str] = &[
+            "x86_64-unknown-linux-gnu",
+            "x86_64-cros-linux-gnu",
+            "x86_64-pc-linux-gnu",
+            "x86_64-apple-darwin",
+        ];
+        const MSAN_SUPPORTED_TARGETS: &[&str] = &[
+            "x86_64-unknown-linux-gnu",
+            "x86_64-cros-linux-gnu",
+            "x86_64-pc-linux-gnu",
+        ];
 
         let supported_targets = match *sanitizer {
             Sanitizer::Address => ASAN_SUPPORTED_TARGETS,