We don't need a -compile-ast clang-cc action, we can just use -S.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82105 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index da533f1..13d9923 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -512,10 +512,7 @@
     } else if (JA.getType() == types::TY_LLVMBC) {
       CmdArgs.push_back("-emit-llvm-bc");
     } else if (JA.getType() == types::TY_PP_Asm) {
-      if (Inputs[0].getType() == types::TY_AST)
-        CmdArgs.push_back("-compile-ast");
-      else
-        CmdArgs.push_back("-S");
+      CmdArgs.push_back("-S");
     } else if (JA.getType() == types::TY_AST) {
       CmdArgs.push_back("-emit-pch");
     }