Revert "AMDGPU: Add 32-bit constant address space"

This reverts commit r324487.

It broke clang tests.

llvm-svn: 324494
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 1af1e10d..b5d43af 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -266,7 +266,7 @@
 
   // 32-bit private, local, and region pointers. 64-bit global, constant and
   // flat.
-    return "e-p:64:64-p1:64:64-p2:64:64-p3:32:32-p4:32:32-p5:32:32-p6:32:32"
+    return "e-p:64:64-p1:64:64-p2:64:64-p3:32:32-p4:32:32-p5:32:32"
          "-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128"
          "-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-A5";
 }