Initial support for code generation from .ast files.
 - Doesn't actually work yet because only module level asm's get correctly marked as externally visible in the PCH.

 - Other things like 'clang-cc foo.ast -ast-dump' now work, as well.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Frontend/ast-codegen.c b/test/Frontend/ast-codegen.c
new file mode 100644
index 0000000..795be92
--- /dev/null
+++ b/test/Frontend/ast-codegen.c
@@ -0,0 +1,5 @@
+// RUN: clang -emit-ast -o %t.ast %s &&
+// RUN: clang -emit-llvm -S -o - %t.ast | FileCheck %s
+
+// CHECK: module asm "foo"
+__asm__("foo");