Add -fcolor-diagnostics to global clang cflags.

Bug: 18187181
Change-Id: Ifcbe34b685b1dfd7ffc801bcdad7bd8208e45f86
diff --git a/core/clang/config.mk b/core/clang/config.mk
index acb425d..4393340 100644
--- a/core/clang/config.mk
+++ b/core/clang/config.mk
@@ -45,7 +45,8 @@
 # Workaround for ccache with clang.
 # See http://petereisentraut.blogspot.com/2011/05/ccache-and-clang.html.
 CLANG_CONFIG_EXTRA_CFLAGS += \
-  -Wno-unused-command-line-argument
+  -Wno-unused-command-line-argument \
+  -fcolor-diagnostics
 
 CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -finline-limit=64 \