[OpenCL] Align fake address space map with the SPIR target maps.

Summary:
We compile user opencl kernel code with spir triple. But built-ins are written in OpenCL and we compile it with triple x86_64 to be able to use x86 intrinsics. And we need address spaces to match in both cases. So, we change fake address space map in OpenCL for matching with spir.

On CPU address spaces are not really important but we'd like to preserve address space information in order to perform optimizations relying on this info like enhanced alias analysis.

Reviewers: pekka.jaaskelainen, Anastasia

Subscribers: pekka.jaaskelainen, yaxunl, bader, cfe-commits

Differential Revision: https://reviews.llvm.org/D28048

llvm-svn: 290436
diff --git a/clang/test/CodeGenOpenCL/str_literals.cl b/clang/test/CodeGenOpenCL/str_literals.cl
index 1c0acd1..8fe5cef 100644
--- a/clang/test/CodeGenOpenCL/str_literals.cl
+++ b/clang/test/CodeGenOpenCL/str_literals.cl
@@ -3,7 +3,7 @@
 __constant char * __constant x = "hello world";
 __constant char * __constant y = "hello world";
 
-// CHECK: unnamed_addr addrspace(3) constant
-// CHECK-NOT: addrspace(3) unnamed_addr constant
-// CHECK: @x = addrspace(3) constant i8 addrspace(3)*
-// CHECK: @y = addrspace(3) constant i8 addrspace(3)*
+// CHECK: unnamed_addr addrspace(2) constant
+// CHECK-NOT: addrspace(2) unnamed_addr constant
+// CHECK: @x = addrspace(2) constant i8 addrspace(2)*
+// CHECK: @y = addrspace(2) constant i8 addrspace(2)*