Reverting r226548 as one of the tests fails in some configurations.

Here's the fail log from our internal setup:
===
  .../tools/clang/clang -cc1 -internal-isystem .../tools/clang/staging/include -nostdsysteminc .../tools/clang/test/CodeGenOpenCL/spir-calling-conv.cl -triple spir-unknown-unknown -emit-llvm -o -
  FileCheck .../tools/clang/test/CodeGenOpenCL/spir-calling-conv.cl
.../tools/clang/test/CodeGenOpenCL/spir-calling-conv.cl:11:12: error: expected string not found in input
 // CHECK: %call = tail call spir_func i32 @get_dummy_id(i32 0)
           ^
<stdin>:6:52: note: scanning from here
define spir_kernel void @foo(i32 addrspace(1)* %A) #0 {
                                                   ^
<stdin>:7:2: note: possible intended match here
 %1 = tail call spir_func i32 @get_dummy_id(i32 0) #2
 ^
===

Here's a failure on a public CI server:
http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_check/1183/

llvm-svn: 226558