[llvm] [Xtensa] Implement Xtensa Region Protection Option and several other small Options. (PR #137135)

[Matt Arsenault via llvm-commits]

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@@ -114,9 +114,13 @@ static DecodeStatus DecodeMR23RegisterClass(MCInst &Inst, uint64_t RegNo,
 }
 
 const MCPhysReg SRDecoderTable[] = {
-    Xtensa::SAR, 3,  Xtensa::ACCLO,      16, Xtensa::ACCHI,       17,
-    Xtensa::M0,  32, Xtensa::M1,         33, Xtensa::M2,          34,
-    Xtensa::M3,  35, Xtensa::WINDOWBASE, 72, Xtensa::WINDOWSTART, 73};
+    Xtensa::LBEG,    0,   Xtensa::LEND,       1,   Xtensa::LCOUNT,      2,
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arsenm wrote:

Same comment as the other patch, this is an MCPHysReg + some other number? 

https://github.com/llvm/llvm-project/pull/137135