cross-build Makefile needs to unset CFLAGS/CXXFLAGS when building the build-side utilities since the flags will be for the cross-compiler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102225 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile b/Makefile
index efbae8d..1421345 100644
--- a/Makefile
+++ b/Makefile
@@ -110,6 +110,8 @@
 	  ENABLE_COVERAGE=$(ENABLE_COVERAGE) \
 	  DISABLE_ASSERTIONS=$(DISABLE_ASSERTIONS) \
 	  ENABLE_EXPENSIVE_CHECKS=$(ENABLE_EXPENSIVE_CHECKS) \
+	  CFLAGS= \
+	  CXXFLAGS= \
 	) || exit 1;
 endif