parser: fix error of -foo.bar() (#9646)

vlib/v/parser/pratt.v

@@ -507,11 +507,7 @@ fn (mut p Parser) prefix_expr() ast.PrefixExpr {
 	// p.warn('unsafe')
 	// }
 	p.next()
-	mut right := if op == .minus {
+	mut right := p.expr(int(token.Precedence.prefix))
-		p.expr(int(token.Precedence.call))
-	} else {
-		p.expr(int(token.Precedence.prefix))
-	}
 	p.is_amp = false
 	if mut right is ast.CastExpr {
 		right.in_prexpr = true

vlib/v/tests/prefix_expr_test.v

@@ -0,0 +1,29 @@
+fn value(n int) int {
+	return n
+}
+
+struct Foo {
+	n int
+}
+
+fn (foo Foo) value() int {
+	return foo.n
+}
+
+fn test_negative() {
+	one := 1
+	negative_one := -1
+	assert -one == negative_one
+	assert one == -negative_one
+
+	assert -value(1) == -1
+
+	// issue #9643
+	foo := Foo{1}
+	assert -foo.value() == -1
+	assert -(foo.value()) == -1
+
+	arr := [1, 2, 3]
+	assert -arr[0] == -1
+	assert -arr[1] == -2
+}