Migrate to to ParseStatus per upstream deprecation.

Author: resistor

llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -7345,7 +7345,7 @@ ParseStatus MipsAsmParser::matchAnyRegisterNameWithoutDollar(
   Index = matchCheriRegisterName(Identifier, Operands);
   if (Index != -1) {
     if (Index == -2)
-      return MatchOperand_ParseFail;
+      return ParseStatus::Failure;
     Operands.push_back(MipsOperand::CreateCheriReg(
         Index, Identifier, getContext().getRegisterInfo(), S, getLexer().getLoc(), *this));
     return ParseStatus::Success;

llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp

@@ -2258,7 +2258,7 @@ ParseStatus RISCVAsmParser::parseSpecialCapRegister(OperandVector &Operands) {
 
   switch (getLexer().getKind()) {
   default:
-    return MatchOperand_NoMatch;
+    return ParseStatus::NoMatch;
   case AsmToken::LParen:
   case AsmToken::Minus:
   case AsmToken::Plus: