Switch to using -fsjlj-exceptions instead of hard-coding it. Notably, this fixes

calls to the UnwindResumeOrRethrow function for C++/Obj-C exception handling,
for Darwin ARM.

llvm-svn: 95787

clang/lib/Frontend/InitPreprocessor.cpp

@@ -279,6 +279,8 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
 
   if (LangOpts.Exceptions)
     Builder.defineMacro("__EXCEPTIONS");
+  if (LangOpts.SjLjExceptions)
+    Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
 
   if (LangOpts.CPlusPlus) {
     Builder.defineMacro("__DEPRECATED");