Disable -Wimplicit-int-float-conversion warning.

Clang's "-Wimplicit-int-float-conversion" fires up at more than
100 places in webrtc-apm.

Disable this warning temporarily before the code can be updated.

BUG=chromium:1024392
TEST=webrtc-apm builds.

Change-Id: I5944cdf8fcb078623774f14dbf1429206db2d085
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/webrtc-apm/+/1923007
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Hsinyu Chao <hychao@chromium.org>

common.mk

diff --git a/common.mk b/common.mk
index 3412287..e05d85a 100644
--- a/common.mk
+++ b/common.mk
@@ -318,7 +318,8 @@
 #  CXXFLAGS := $(filter-out badflag,$(CXXFLAGS)) # Filter out a value
 # The same goes for CFLAGS.
 COMMON_CFLAGS-gcc := -fvisibility=internal -ggdb3 -Wa,--noexecstack
-COMMON_CFLAGS-clang := -fvisibility=hidden -ggdb
+COMMON_CFLAGS-clang := -fvisibility=hidden -ggdb \
+  -Wno-implicit-int-float-conversion
 COMMON_CFLAGS := -Wall -Wunused -Wno-unused-parameter -Werror -Wformat=2 \
   -fno-strict-aliasing $(SSP_CFLAGS) -O1
 CXXFLAGS += $(COMMON_CFLAGS) $(COMMON_CFLAGS-$(CXXDRIVER)) -std=gnu++14