Frontend: Add FrontendAction support for handling LLVM IR inputs.
 - These inputs follow an abbreviated execution path, but are still worth handling by FrontendAction so they reuse all the other clang -cc1 features.

llvm-svn: 105582
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 28000bb..68e7ac1 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -334,6 +334,8 @@
          "Invocation must have exactly one source file!");
   assert(Clang.getFrontendOpts().Inputs[0].first != IK_AST &&
          "FIXME: AST inputs not yet supported here!");
+  assert(Clang.getFrontendOpts().Inputs[0].first != IK_LLVM_IR &&
+         "IR inputs not support here!");
 
   // Create the AST unit.
   AST.reset(new ASTUnit(false));