Use mingw on Windows.

LOCAL_CLANG := true is a no-op on Linux/Darwin host builds, but
apparently moves Windows binaries from mingw to clang, which is
completely untested.

Change-Id: Ibbc468d4a19a9e36bbcb93aa030fcc771af020ba
diff --git a/Android.mk b/Android.mk
index 0e1a9b6..17d6ece 100644
--- a/Android.mk
+++ b/Android.mk
@@ -56,7 +56,6 @@
 # ------------------------------------------------------------------------------
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbase
-LOCAL_CLANG := true
 LOCAL_SRC_FILES := $(libbase_src_files)
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_CPPFLAGS := $(libbase_cppflags)
@@ -66,7 +65,6 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbase
-LOCAL_CLANG := true
 LOCAL_WHOLE_STATIC_LIBRARIES := libbase
 LOCAL_SHARED_LIBRARIES := liblog
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
@@ -88,7 +86,6 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbase_test
-LOCAL_CLANG := true
 LOCAL_SRC_FILES := $(libbase_test_src_files)
 LOCAL_CPPFLAGS := $(libbase_cppflags)
 LOCAL_SHARED_LIBRARIES := libbase