feat(disasm): name the CLDEMOTE encoding the decoder refuses

The hint NOP opcode 0F 1C /r with a memory operand is CLDEMOTE, a
memory-only instruction the toolchain's own table carries; the decoder
rejects the encoding instead of naming it.  The rejected-encoding side
of the supplementary table names it from the bytes, and the corpus row
0f1c03 pins the text in the unlisted fixture, round trip byte exact.

Assisted-by: GLM 5.3 Flash

disasm/disasm.go

@@ -68,6 +68,12 @@ func Decode(a arch.Arch, code []byte, addr uint64) (Instruction, error) {
 	default: // amd64
 		inst, err := x86asm.Decode(code, 64)
 		if err != nil {
+			// A few named families the decoder refuses outright live in
+			// the same supplementary table; anything else keeps the
+			// placeholder.
+			if text, n, ok := nameAMD64Rejected(code); ok {
+				return Instruction{Addr: addr, Text: text, Len: n}, nil
+			}
 			return Instruction{Addr: addr, Text: "???", Len: 1}, nil
 		}
 		if inst.Op == 0 {