[clang] Add no-warn support for Wa

llvm-svn: 368328
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 60ce517..cb38056 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -493,6 +493,7 @@
       CodeGenOpts.IncrementalLinkerCompatible;
   Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
+  Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
   Options.MCOptions.ABIName = TargetOpts.ABI;