fix(parser): fold a signed parenthesised displacement expression

Assisted-by: GLM 5.3 Flash

parser/parser.go

@@ -552,6 +552,20 @@ func parseAddress(g []token.Token) ast.Address {
 			i = len(g) - len(rest)
 		}
 	}
+	// The same expression under a leading sign: -(24+8)(X6) puts the sign
+	// outside the fold.  The base group must follow for the value to
+	// commit, exactly as in the unsigned branch above.
+	if i < len(g) && (g[i].Kind == token.Minus || g[i].Kind == token.Plus) &&
+		i+1 < len(g) && g[i+1].Kind == token.LParen {
+		if v, rest, ok := foldExpr(g[i+1:]); ok && len(rest) > 0 && rest[0].Kind == token.LParen {
+			if g[i].Kind == token.Minus {
+				v = -v
+			}
+			addr.Offset = v
+			addr.HasOff = true
+			i = len(g) - len(rest)
+		}
+	}
 	// Optional leading displacement before a '(' base group.  A sign pushes
 	// the parenthesis one token further out: -4(DX) has it at i+2.
 	if isSignedNumber(g, i) {