[llvm] [MIR] Fix vreg flag vector memory leak (PR #112479)

[Akshat Oke via llvm-commits]

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@@ -703,7 +703,7 @@ bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
         return error(FlagStringValue.SourceRange.Start,
                      Twine("use of undefined register flag '") +
                          FlagStringValue.Value + "'");
-      Info.Flags.push_back(FlagValue);
+      Info.Flags |= FlagValue;
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optimisan wrote:

Added the check but can't be tested till relanding the WWM_REG flag patch.

https://github.com/llvm/llvm-project/pull/112479