RISC-V: Fix warning in predicated.md

Notice there is warning in predicates.md:
../../../riscv-gcc/gcc/config/riscv/predicates.md: In function ‘bool arith_operand_or_mode_mask(rtx, machine_mode)’:
../../../riscv-gcc/gcc/config/riscv/predicates.md:33:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             (match_test "INTVAL (op) == GET_MODE_MASK (HImode)
../../../riscv-gcc/gcc/config/riscv/predicates.md:34:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     || INTVAL (op) == GET_MODE_MASK (SImode)"))))

gcc/ChangeLog:

	* config/riscv/predicates.md: Change INTVAL into UINTVAL.

gcc/config/riscv/predicates.md

@@ -31,7 +31,7 @@
   (ior (match_operand 0 "arith_operand")
        (and (match_code "const_int")
             (match_test "INTVAL (op) == GET_MODE_MASK (HImode)
-			 || INTVAL (op) == GET_MODE_MASK (SImode)"))))
+			 || UINTVAL (op) == GET_MODE_MASK (SImode)"))))
 
 (define_predicate "lui_operand"
   (and (match_code "const_int")