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/kernel-args.ll b/llvm/test/CodeGen/AMDGPU/kernel-args.ll
index b1f20fd..95a6831 100644
--- a/llvm/test/CodeGen/AMDGPU/kernel-args.ll
+++ b/llvm/test/CodeGen/AMDGPU/kernel-args.ll
@@ -1,5 +1,5 @@
 ; RUN: llc < %s -march=amdgcn -verify-machineinstrs | FileCheck %s --check-prefixes=SI,GCN,MESA-GCN,FUNC
-; RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s --check-prefixes=VI,GCN,MESA-VI,MESA-GCN,FUNC
+; RUN: llc < %s -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs | FileCheck %s --check-prefixes=VI,GCN,MESA-VI,MESA-GCN,FUNC
 ; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=fiji -verify-machineinstrs | FileCheck %s --check-prefixes=VI,GCN,HSA-VI,FUNC
 ; RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s --check-prefix=EG --check-prefix=FUNC
 ; RUN: llc < %s -march=r600 -mcpu=cayman | FileCheck %s --check-prefix=EG --check-prefix=FUNC