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/fract.ll b/llvm/test/CodeGen/AMDGPU/fract.ll
index 7d713f4..4e1a503 100644
--- a/llvm/test/CodeGen/AMDGPU/fract.ll
+++ b/llvm/test/CodeGen/AMDGPU/fract.ll
@@ -1,8 +1,8 @@
 ; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN-SAFE -check-prefix=GCN -check-prefix=SI %s
 ; RUN: llc -march=amdgcn -mcpu=bonaire -verify-machineinstrs < %s | FileCheck -check-prefix=GCN-SAFE -check-prefix=GCN -check-prefix=CI %s
-; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefix=GCN-SAFE -check-prefix=GCN -check-prefix=FUNC %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -check-prefix=GCN-SAFE -check-prefix=GCN -check-prefix=FUNC %s
 ; RUN: llc -march=amdgcn -verify-machineinstrs -enable-unsafe-fp-math < %s | FileCheck -check-prefix=GCN-UNSAFE -check-prefix=GCN %s
-; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -enable-unsafe-fp-math < %s | FileCheck -check-prefix=GCN-UNSAFE -check-prefix=GCN %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs -enable-unsafe-fp-math < %s | FileCheck -check-prefix=GCN-UNSAFE -check-prefix=GCN %s
 
 declare float @llvm.fabs.f32(float) #0
 declare float @llvm.floor.f32(float) #0