[llvm] [RISCV][AsmParser] Allow parsing vset{i}vli omitting LMUL parameter (PR #115277)

[Pengcheng Wang via llvm-commits]

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@@ -2320,7 +2326,7 @@ bool RISCVAsmParser::generateVTypeError(SMLoc ErrorLoc) {
   return Error(
       ErrorLoc,
       "operand must be "
-      "e[8|16|32|64],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]");
+      "e{8|16|32|64},[m{1|2|4|8|f2|f4|f8},]{ta|tu},{ma|mu}");
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wangpc-pp wrote:

All right, please use `e{8|16|32|64}[,m{1|2|4|8|f2|f4|f8}],{ta|tu},{ma|mu}` (put `[` in front of `,`) in case we may support optional policies someday.

https://github.com/llvm/llvm-project/pull/115277