make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94378 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Makefile.unittest b/unittests/Makefile.unittest
index e417435..656f5e2 100644
--- a/unittests/Makefile.unittest
+++ b/unittests/Makefile.unittest
@@ -14,6 +14,8 @@
 # Set up variables for building a unit test.
 ifdef TESTNAME
 
+REQUIRES_RTTI = 1
+
 include $(LEVEL)/Makefile.common
 
 LLVMUnitTestExe = $(BuildMode)/$(TESTNAME)Tests$(EXEEXT)