[llvm] [Xtensa] Implement base CallConvention. (PR #83280)

[Matt Arsenault via llvm-commits]

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@@ -686,6 +767,58 @@ bool XtensaAsmParser::ParseInstruction(ParseInstructionInfo &Info,
   return false;
 }
 
+bool XtensaAsmParser::parseLiteralDirective(SMLoc L) {
+  MCAsmParser &Parser = getParser();
+  MCSymbol *Sym;
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arsenm wrote:

Sink this down to define on first use 

https://github.com/llvm/llvm-project/pull/83280