[llvm] [AMDGPU] Tolerate AMDGPUTargetELFStreamer without initializeTargetID (PR #226495)

[Tim Renouf via llvm-commits]

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@@ -209,6 +209,18 @@ class AMDGPUTargetELFStreamer final : public AMDGPUTargetStreamer {
   unsigned getEFlagsV4();
   unsigned getEFlagsV6();
 
+  // Override of AMDGPUTargetStreamer::getTargetID that tolerates
+  // initializeTargetID not having been called by initializing it here from our
+  // MCSubtargetInfo. This allows the use of AMDGPUTargetELFStreamer in an
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trenouf wrote:

AMDGPUTargetStreamer::initializeTargetID takes an MCSubtargetInfo. AMDGPUTargetELFStreamer has an MCSubtargetInfo already. Are you saying that is all in flux and my approach here will stop working at some point in the future? Do you have another suggestion for this use case?

https://github.com/llvm/llvm-project/pull/226495