R600: Handle -mcpu option v3

v2:
  - Add a test case

v3:
  - Use the -### clang option in the tests

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178499 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.h b/lib/Driver/Tools.h
index 0d215ea..d647171 100644
--- a/lib/Driver/Tools.h
+++ b/lib/Driver/Tools.h
@@ -51,6 +51,7 @@
                           bool KernelOrKext) const;
     void AddMIPSTargetArgs(const ArgList &Args, ArgStringList &CmdArgs) const;
     void AddPPCTargetArgs(const ArgList &Args, ArgStringList &CmdArgs) const;
+    void AddR600TargetArgs(const ArgList &Args, ArgStringList &CmdArgs) const;
     void AddSparcTargetArgs(const ArgList &Args, ArgStringList &CmdArgs) const;
     void AddX86TargetArgs(const ArgList &Args, ArgStringList &CmdArgs) const;
     void AddHexagonTargetArgs (const ArgList &Args, ArgStringList &CmdArgs) const;