Work-around OS flex differences.

Linux flex generates declarations with int vs Darwin with size_t.
Switch host build to clang for better error messages. Disable Werror
until errors are dealt with.

Change-Id: I0abc8923dd1e57d55e8f318c7d1fcf8f8c975571
diff --git a/mcld-device-build.mk b/mcld-device-build.mk
index 87bc0b7..744edcf 100644
--- a/mcld-device-build.mk
+++ b/mcld-device-build.mk
@@ -23,6 +23,10 @@
     -UNDEBUG
 endif
 
+ifeq ($(HOST_OS),darwin)
+LOCAL_CFLAGS += -DDARWIN_FLEX=1
+endif
+
 # Make sure bionic is first so we can include system headers.
 LOCAL_C_INCLUDES := \
   bionic \