Produce an error when trying to link with -emit-llvm.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189193 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index a309625..de58962 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -1171,6 +1171,10 @@
   Arg *FinalPhaseArg;
   phases::ID FinalPhase = getFinalPhase(Args, &FinalPhaseArg);
 
+  if (FinalPhase == phases::Link && Args.hasArg(options::OPT_emit_llvm)) {
+    Diag(clang::diag::err_drv_emit_llvm_link);
+  }
+
   // Reject -Z* at the top level, these options should never have been exposed
   // by gcc.
   if (Arg *A = Args.getLastArg(options::OPT_Z_Joined))