[llvm] [AMDGPU] Let LowerModuleLDS run twice on the same module (PR #81729)

[Jon Chesterfield via llvm-commits]

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@@ -327,16 +327,18 @@ class AMDGPULowerModuleLDS {
     return convertUsersOfConstantsToInstructions(LDSGlobals);
   }
 
+  std::optional<bool> HasAbsoluteGVs;
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JonChesterfield wrote:

This is only used by one function, make it a local variable and reinstate the static annotations. Minimising scope of mutable state is important.

https://github.com/llvm/llvm-project/pull/81729