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
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index fbb1136..fda0875 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -176,6 +176,8 @@
 
   virtual bool UseDwarfDebugFlags() const;
 
+  virtual bool UseSjLjExceptions() const;
+
   /// }
 };