[TableGen] Fix GIMT_Encode8 with a large argument (#153429)

    error: integer literal is too large to be represented
    in a signed integer type, interpreting as unsigned
    [-Werror,-Wimplicitly-unsigned-literal]

Introduced in #153391

Author: pfusik

llvm/test/TableGen/GlobalISelCombinerEmitter/match-table.td

@@ -181,7 +181,7 @@ def MyCombiner: GICombiner<"GenMyCombiner", [
 // CHECK-NEXT:       GIM_RecordInsnIgnoreCopies, /*DefineMI*/1, /*MI*/0, /*OpIdx*/1, // MIs[1]
 // CHECK-NEXT:       GIM_CheckOpcode, /*MI*/1, GIMT_Encode2(TargetOpcode::G_CONSTANT),
 // CHECK-NEXT:       // MIs[1] z
-// CHECK-NEXT:       GIM_CheckLiteralInt, /*MI*/1, /*Op*/1, GIMT_Encode8(18446744073709551574),
+// CHECK-NEXT:       GIM_CheckLiteralInt, /*MI*/1, /*Op*/1, GIMT_Encode8(18446744073709551574u),
 // CHECK-NEXT:       GIM_CheckConstantInt8, /*MI*/0, /*Op*/2, 43,
 // CHECK-NEXT:       GIM_CheckIsSafeToFold, /*NumInsns*/1,
 // CHECK-NEXT:       // Combiner Rule #5: InOutInstTest1

llvm/test/TableGen/GlobalISelEmitter/int64min.td

@@ -17,12 +17,12 @@ def ANDI : I<(outs GPR:$dst), (ins GPR:$src1, i64imm:$src2), []>;
 // CHECK-NEXT: GIM_RootCheckRegBankForClass, /*Op*/1, /*RC*/GIMT_Encode2(MyTarget::GPRRegClassID),
 // CHECK-NEXT: // MIs[0] Operand 2
 // CHECK-NEXT: GIM_RootCheckType, /*Op*/2, /*Type*/GILLT_s64,
-// CHECK-NEXT: GIM_CheckConstantInt, /*MI*/0, /*Op*/2, GIMT_Encode8(9223372036854775808),
+// CHECK-NEXT: GIM_CheckConstantInt, /*MI*/0, /*Op*/2, GIMT_Encode8(9223372036854775808u),
 // CHECK-NEXT: // (and:{ *:[i64] } GPR:{ *:[i64] }:$rs1, -9223372036854775808:{ *:[i64] })  =>  (ANDI:{ *:[i64] } GPR:{ *:[i64] }:$rs1, -9223372036854775808:{ *:[i64] })
 // CHECK-NEXT: GIR_BuildRootMI, /*Opcode*/GIMT_Encode2(MyTarget::ANDI),
 // CHECK-NEXT: GIR_RootToRootCopy, /*OpIdx*/0, // DstI[dst]
 // CHECK-NEXT: GIR_RootToRootCopy, /*OpIdx*/1, // rs1
-// CHECK-NEXT: GIR_AddImm, /*InsnID*/0, /*Imm*/GIMT_Encode8(9223372036854775808),
+// CHECK-NEXT: GIR_AddImm, /*InsnID*/0, /*Imm*/GIMT_Encode8(9223372036854775808u),
 // CHECK-NEXT: GIR_RootConstrainSelectedInstOperands,
 // CHECK-NEXT: // GIR_Coverage, 0,
 // CHECK-NEXT: GIR_EraseRootFromParent_Done,

llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp

@@ -241,6 +241,8 @@ MatchTableRecord MatchTable::IntValue(unsigned NumBytes, int64_t IntValue) {
   if (NumBytes < 8)
     UIntValue &= (UINT64_C(1) << NumBytes * 8) - 1;
   std::string Str = llvm::to_string(UIntValue);
+  if (UIntValue > INT64_MAX)
+    Str += 'u';
   // TODO: Could optimize this directly to save the compiler some work when
   // building the file
   return MatchTableRecord(std::nullopt, Str, NumBytes,