Enable clang compilation with libc but not linker.

Clang is still disabled for x86 and x86_64 long double code,
for x86_64 special assembly instruction, and the linker module.

BUG: 17163651
BUG: 17302991
BUG: 17403674

(cherry picked from commit b58db8b083ce41798a5310616e4f20885cec611f)

Change-Id: I916c05056d37a9c287b0a5ae3b1a209d98c8f70e
diff --git a/linker/linker_executable.mk b/linker/linker_executable.mk
index 4902a0c..a596a48 100644
--- a/linker/linker_executable.mk
+++ b/linker/linker_executable.mk
@@ -9,6 +9,8 @@
 LOCAL_MODULE_CLASS := EXECUTABLES
 LOCAL_MODULE_SUFFIX := $(TARGET_EXECUTABLE_SUFFIX)
 
+# Clang calls /usr/bin/ld: unrecognized option '--icf=safe', http://b/17403674.
+LOCAL_CLANG := false
 include $(BUILD_SYSTEM)/dynamic_binary.mk
 
 # See build/core/executable_internal.mk