yasm: Respect portage host cc variable

Pass CC_FOR_BUILD and CCLD_FOR_BUILD to econf.
Otherwise it invokes cc instead of portage specified HOST/BUILD CC.

Gentoo PR: https://github.com/gentoo/gentoo/pull/16180

BUG=chromium:979916, chromium:991812, chromium:1093608
TEST=CQ

Change-Id: I4cad14fa11212b3a3cc4e3d66bf886cbe49651f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2238520
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Manoj Gupta <manojgupta@chromium.org>
diff --git a/dev-lang/yasm/yasm-1.3.0.ebuild b/dev-lang/yasm/yasm-1.3.0-r1.ebuild
similarity index 88%
rename from dev-lang/yasm/yasm-1.3.0.ebuild
rename to dev-lang/yasm/yasm-1.3.0-r1.ebuild
index 43947fd..63e5505 100644
--- a/dev-lang/yasm/yasm-1.3.0.ebuild
+++ b/dev-lang/yasm/yasm-1.3.0-r1.ebuild
@@ -5,7 +5,7 @@
 
 PYTHON_COMPAT=( python2_7 )
 
-inherit python-r1
+inherit python-r1 toolchain-funcs
 
 DESCRIPTION="An assembler for x86 and x86_64 instruction sets"
 HOMEPAGE="http://yasm.tortall.net/"
@@ -30,6 +30,8 @@
 
 	XMLTO=: \
 	econf \
+		CC_FOR_BUILD=$(tc-getBUILD_CC) \
+		CCLD_FOR_BUILD=$(tc-getBUILD_CC) \
 		$(use_enable python) \
 		$(use_enable python python-bindings) \
 		$(use_enable nls)