[llvm] Extend MemoryEffects to Support Target-Specific Memory Locations (PR #148650)

[Paul Walker via llvm-commits]

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@@ -203,6 +203,8 @@ enum Kind {
   kw_readwrite,
   kw_argmem,
   kw_inaccessiblemem,
+  kw_aarch64_fpmr,
+  kw_aarch64_za,
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paulwalker-arm wrote:

I had in mind that these would be part of the follow-on PR as well?  The idea being this PR keeps everything generic and fully supports `target_mem#` (i.e. both printing and parsing). 

https://github.com/llvm/llvm-project/pull/148650