[llvm] [AMDGPU] Make LowerModuleLDS a noop on an already lowered module (PR #217075)

[Arseniy Obolenskiy via llvm-commits]

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@@ -1078,17 +1078,23 @@ class AMDGPULowerModuleLDS {
   }
 
   bool runOnModuleNormal(Module &M) {
-    CallGraph CG = CallGraph(M);
     bool Changed = superAlignLDSGlobals(M);
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aobolensk wrote:

that's reasonable, moved it after the early return

https://github.com/llvm/llvm-project/pull/217075