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/SIMachineFunctionInfo.cpp b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
index 2534ad0..888d8f9 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
@@ -47,8 +47,7 @@
     WorkItemIDZ(false),
     ImplicitBufferPtr(false),
     ImplicitArgPtr(false),
-    GITPtrHigh(0xffffffff),
-    HighBitsOf32BitAddress(0) {
+    GITPtrHigh(0xffffffff) {
   const SISubtarget &ST = MF.getSubtarget<SISubtarget>();
   const Function &F = MF.getFunction();
   FlatWorkGroupSizes = ST.getFlatWorkGroupSizes(F);
@@ -165,11 +164,6 @@
   StringRef S = A.getValueAsString();
   if (!S.empty())
     S.consumeInteger(0, GITPtrHigh);
-
-  A = F.getFnAttribute("amdgpu-32bit-address-high-bits");
-  S = A.getValueAsString();
-  if (!S.empty())
-    S.consumeInteger(0, HighBitsOf32BitAddress);
 }
 
 unsigned SIMachineFunctionInfo::addPrivateSegmentBuffer(