Enable FeatureFlatForGlobal on Volcanic Islands

This switches to the workaround that HSA defaults to
for the mesa path.

This should be applied to the 4.0 branch.

Patch by Vedran Miletić <vedran@miletic.net>

llvm-svn: 292982
diff --git a/llvm/test/CodeGen/AMDGPU/flat-scratch-reg.ll b/llvm/test/CodeGen/AMDGPU/flat-scratch-reg.ll
index f15cbef..b71c8bc 100644
--- a/llvm/test/CodeGen/AMDGPU/flat-scratch-reg.ll
+++ b/llvm/test/CodeGen/AMDGPU/flat-scratch-reg.ll
@@ -5,7 +5,7 @@
 ; RUN: llc -march=amdgcn -mcpu=stoney -mattr=-xnack -verify-machineinstrs < %s | FileCheck -check-prefix=VI-NOXNACK  -check-prefix=GCN %s
 
 ; RUN: llc -march=amdgcn -mcpu=carrizo -verify-machineinstrs < %s | FileCheck -check-prefix=VI-XNACK  -check-prefix=GCN %s
-; RUN: llc -march=amdgcn -mcpu=stoney -verify-machineinstrs < %s | FileCheck -check-prefix=VI-XNACK  -check-prefix=GCN %s
+; RUN: llc -march=amdgcn -mcpu=stoney  -verify-machineinstrs < %s | FileCheck -check-prefix=VI-XNACK  -check-prefix=GCN %s
 
 ; RUN: llc -march=amdgcn -mtriple=amdgcn--amdhsa -mcpu=kaveri -verify-machineinstrs < %s | FileCheck -check-prefix=HSA-CI -check-prefix=GCN %s
 ; RUN: llc -march=amdgcn -mtriple=amdgcn--amdhsa -mcpu=carrizo -mattr=-xnack -verify-machineinstrs < %s | FileCheck -check-prefix=HSA-VI-NOXNACK -check-prefix=GCN %s