Implement nans, prefetch, and trap builtins.  

This closes <rdar://problem/6080720>, support for __builtin_constant_p
has been filed separately.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@53885 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 714256a..d34e7f3 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -909,6 +909,7 @@
   bool SemaBuiltinUnorderedCompare(CallExpr *TheCall);
   bool SemaBuiltinStackAddress(CallExpr *TheCall);
   Action::ExprResult SemaBuiltinShuffleVector(CallExpr *TheCall);
+  bool SemaBuiltinPrefetch(CallExpr *TheCall); 
   void CheckPrintfArguments(CallExpr *TheCall,
                             bool HasVAListArg, unsigned format_idx);
   void CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,