clang-cl: Implement /GL in terms of -flto.

No documentation yet; the linker needs more work.

Differential Revision: http://reviews.llvm.org/D10270

llvm-svn: 239213
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 059f424..a04a1f8 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -1744,7 +1744,7 @@
   // Determine what the derived output name should be.
   const char *NamedOutput;
 
-  if (JA.getType() == types::TY_Object &&
+  if ((JA.getType() == types::TY_Object || JA.getType() == types::TY_LTO_BC) &&
       C.getArgs().hasArg(options::OPT__SLASH_Fo, options::OPT__SLASH_o)) {
     // The /Fo or /o flag decides the object filename.
     StringRef Val = C.getArgs().getLastArg(options::OPT__SLASH_Fo,