Escape % in diagnostic message when compiling LLVM IR.

% is a common character in IR so we'd crash on almost any malformed IR. The
diagnostic formatter expects a formatting directive when it sees an unescaped %.

llvm-svn: 152956
diff --git a/clang/test/Frontend/ir-support-errors.ll b/clang/test/Frontend/ir-support-errors.ll
index 98227d4..cb5913c 100644
--- a/clang/test/Frontend/ir-support-errors.ll
+++ b/clang/test/Frontend/ir-support-errors.ll
@@ -3,6 +3,6 @@
 target triple = "x86_64-apple-darwin10"
 
 define i32 @f0() nounwind ssp {
-; CHECK: {{.*}}ir-support-errors.ll:7:16: error: expected value token
-       ret i32 x
+; CHECK: {{.*}}ir-support-errors.ll:7:16: error: use of undefined value '%x'
+       ret i32 %x
 }