[llvm] [ARM][TableGen][MC] Change the ARM mnemonic operands to be optional for ASM parsing (PR #83436)

[Sergei Barannikov via llvm-commits]

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@@ -4053,6 +4073,63 @@ static MCRegister MatchRegisterName(StringRef Name);
 
 /// }
 
+static const DenseSet<StringRef> DataTypes{
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s-barannikov wrote:

This should be moved inside isDataTypeToken to avoid start-up initialization cost.


https://github.com/llvm/llvm-project/pull/83436