7151898: Check for LANG in Mac OS X jdk build sanity check [macosx]

Reviewed-by: ohair, smarks

make/common/shared/Sanity.gmk

@@ -348,7 +348,13 @@ ifneq ($(PLATFORM), windows)
 	    "        Try setting LANG to 'C'. \n" \
 	    "" >> $(WARNING_FILE) ; \
         fi
+ifeq ($(PLATFORM), macosx)
+	@if [ "$(LANG)" = "" ]; then \
+	  $(ECHO) "ERROR: LANG must be set on Mac OS X. Recommended value is \"C\"" >> $(ERROR_FILE) ; \
+	fi
 endif
+endif
+
 
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 # Check the Windows cygwin version