rewriter tests are darwin specific, don't run them on other platforms.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@48168 91177308-0d34-0410-b5e6-96231b3b80d8

test/Makefile

@@ -1,8 +1,14 @@
 LEVEL = ../../..
 include $(LEVEL)/Makefile.common
 
+TESTDIRS := CodeGen Lexer Preprocessor Parser Sema Analysis Serialization
+
+# Only run rewriter tests on darwin.
+ifeq ($(OS),Darwin)
+TESTDIRS += Rewriter
+endif
+
 all::
-	PATH=$$PATH:$(ToolDir):$(LLVM_SRC_ROOT)/test/Scripts find\
-	     Rewriter CodeGen Lexer Preprocessor Parser Sema Analysis Serialization\
-	     \( -name '*.c' -or -name '*.cpp' -or -name '*.m' \)\
+	PATH=$$PATH:$(ToolDir):$(LLVM_SRC_ROOT)/test/Scripts \
+          find $(TESTDIRS) \( -name '*.c' -or -name '*.cpp' -or -name '*.m' \) \
 	      -print -exec ./TestRunner.sh {} \;