[llvm] [RISCV] Error out on incorrectly spelt @plt on call symbols (PR #135324)

[Jessica Clarke via llvm-commits]

================
@@ -2123,22 +2123,25 @@ ParseStatus RISCVAsmParser::parseCallSymbol(OperandVector &Operands) {
 
   if (getLexer().getKind() != AsmToken::Identifier)
     return ParseStatus::NoMatch;
+
   std::string Identifier(getTok().getIdentifier());
+  SMLoc E = getTok().getEndLoc();
 
   if (getLexer().peekTok().is(AsmToken::At)) {
     Lex();
     Lex();
     StringRef PLT;
+    SMLoc PLTLoc = getLoc();
     if (getParser().parseIdentifier(PLT) || PLT != "plt")
----------------
jrtc27 wrote:

I went looking in binutils. It's only ever done `strcmp("@plt")` since the first commit of RISC-V support, and has ignored it since Sep 2022 / 2.40. So case-sensitive is fine.

https://github.com/llvm/llvm-project/pull/135324