[llvm] [WebAssembly] Unify type checking in AsmTypeCheck (PR #110094)

[Derek Schuff via llvm-commits]

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@@ -21,25 +21,48 @@
 #include "llvm/MC/MCParser/MCAsmParser.h"
 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
 #include "llvm/MC/MCSymbol.h"
+#include <variant>
 
 namespace llvm {
 
 class WebAssemblyAsmTypeCheck final {
   MCAsmParser &Parser;
   const MCInstrInfo &MII;
 
-  SmallVector<wasm::ValType, 8> Stack;
+  struct Ref : public std::monostate {};
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dschuff wrote:

Is there any advantage to deriving from std::monostate compared to just
`using Ref = std::monostate`?

https://github.com/llvm/llvm-project/pull/110094