parser: return node on incomplete module selector (#7574)

vlib/v/parser/parser.v

@@ -1153,6 +1153,11 @@ pub fn (mut p Parser) name_expr() ast.Expr {
 				if p.peek_tok.kind == .dot &&
 					p.peek_tok2.kind != .eof && p.peek_tok2.lit.len > 0 && p.peek_tok2.lit[0].is_capital() {
 					is_mod_cast = true
+				} else if p.peek_tok.kind == .dot &&
+					p.peek_tok2.kind != .eof && p.peek_tok2.lit.len == 0 {
+					// incomplete module selector must be handled by dot_expr instead
+					node = p.parse_ident(language)
+					return node
 				}
 			}
 			// prepend the full import

vlib/v/parser/tests/uncomplete_module_call_err.out

@@ -1,4 +1,4 @@
-vlib/v/parser/tests/uncomplete_module_call_err.vv:7:1: error: unexpected token ``
+vlib/v/parser/tests/uncomplete_module_call_err.vv:7:1: error: unexpected `}`, expecting `name`
     5 | fn main() {
     6 |     os.
     7 | }