[RISCV] Fix the predicate code of uimm6

[kito-cheng]

LGTM

[asb]

Good catch.

[craig.topper]

Is it possible to add a test for this?

[craig.topper]

In D156974#4558402, @craig.topper wrote:

Is it possible to add a test for this?

Test added in 40f3708205430a7a562d58f48fd9c294fb80d5e0

llvm/lib/Target/RISCV/RISCVInstrInfo.td

 
 def InsnDirectiveOpcode : AsmOperandClass {
   let Name = "InsnDirectiveOpcode";
   let ParserMethod = "parseInsnDirectiveOpcode";
   let RenderMethod = "addImmOperands";
   let PredicateMethod = "isImm";
 }
 
-def uimm6 : Operand<XLenVT>, ImmLeaf<XLenVT, [{return isInt<6>(Imm);}]> {
+def uimm6 : Operand<XLenVT>, ImmLeaf<XLenVT, [{return isUInt<6>(Imm);}]> {
   let ParserMatchClass = UImmAsmOperand<6>;
   let DecoderMethod = "decodeUImmOperand<6>";
   let OperandType = "OPERAND_UIMM6";
   let OperandNamespace = "RISCVOp";
 }
 
 def uimm7_opcode : Operand<XLenVT> {
   let ParserMatchClass = InsnDirectiveOpcode;