AMDGPU: Stop forcing internalize at -O0

[arsenm]

Summary

This doesn't really matter if clang is always emitting
the visibility as hidden by default.

[rampitec]

LGTM

[arsenm]

r341168

lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

void AMDGPUTargetMachine::adjustPassManager(PassManagerBuilder &Builder) {
   bool AMDGPUAA = EnableAMDGPUAliasAnalysis && EnableOpt;
   bool LibCallSimplify = EnableLibCallSimplify && EnableOpt;
 
   if (EnableAMDGPUFunctionCalls) {
     delete Builder.Inliner;
     Builder.Inliner = createAMDGPUFunctionInliningPass();
   }
 
-  if (Internalize) {
-    // If we're generating code, we always have the whole program available. The
-    // relocations expected for externally visible functions aren't supported,
-    // so make sure every non-entry function is hidden.
-    Builder.addExtension(
-      PassManagerBuilder::EP_EnabledOnOptLevel0,
-      [](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
-        PM.add(createInternalizePass(mustPreserveGV));
-      });
-  }
-
   Builder.addExtension(
     PassManagerBuilder::EP_ModuleOptimizerEarly,
     [Internalize, EarlyInline, AMDGPUAA](const PassManagerBuilder &,
                                          legacy::PassManagerBase &PM) {
       if (AMDGPUAA) {
         PM.add(createAMDGPUAAWrapperPass());
         PM.add(createAMDGPUExternalAAWrapperPass());
       }

test/CodeGen/AMDGPU/internalize.ll

 ; RUN: opt -O1 -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=ALL -check-prefix=OPT %s
 ; RUN: opt -O0 -S -mtriple=amdgcn-unknown-amdhsa -amdgpu-internalize-symbols < %s | FileCheck -check-prefix=ALL -check-prefix=OPTNONE %s
 
 ; OPT-NOT: gvar_unused
 ; OPTNONE: gvar_unused
 @gvar_unused = addrspace(1) global i32 undef, align 4
 
 ; ALL: gvar_used
 @gvar_used = addrspace(1) global i32 undef, align 4
 
-; ALL: define internal fastcc void @func_used_noinline(
+; OPT: define internal fastcc void @func_used_noinline(
+; OPT-NONE: define fastcc void @func_used_noinline(
 define fastcc void @func_used_noinline(i32 addrspace(1)* %out, i32 %tid) #1 {
 entry:
   store volatile i32 %tid, i32 addrspace(1)* %out
   ret void
 }
 
-; OPTNONE: define internal fastcc void @func_used_alwaysinline(
+; OPTNONE: define fastcc void @func_used_alwaysinline(
 ; OPT-NOT: @func_used_alwaysinline
 define fastcc void @func_used_alwaysinline(i32 addrspace(1)* %out, i32 %tid) #2 {
 entry:
   store volatile i32 %tid, i32 addrspace(1)* %out
   ret void
 }
 
-; OPTNONE: define internal void @func_unused(
+; OPTNONE: define void @func_unused(
 ; OPT-NOT: @func_unused
 define void @func_unused(i32 addrspace(1)* %out, i32 %tid) #1 {
 entry:
   store volatile i32 %tid, i32 addrspace(1)* %out
   ret void
 }
 
 ; ALL: define amdgpu_kernel void @kernel_unused(