parser: fix treating JS fn calls as type casts (#6779)

vlib/v/gen/js/tests/js.v

@@ -30,6 +30,7 @@ fn class(extends string, instanceof int) {
 fn main() {
 	println('Hello from V.js!')
 	println(JS.Math.atan2(1, 0))
+	println(JS.eval("console.log('Hello!')"))
 	mut a := 1
 	a *= 2
 	a += 3

vlib/v/parser/parser.v

@@ -1062,7 +1062,7 @@ pub fn (mut p Parser) name_expr() ast.Expr {
 		// if name in table.builtin_type_names {
 		if (!known_var && (name in p.table.type_idxs ||
 			name_w_mod in p.table.type_idxs) && name !in ['C.stat', 'C.sigaction']) ||
-			is_mod_cast || (!(name.len > 1 && name[0] == `C` && name[1] == `.`) && name[0].is_capital()) {
+			is_mod_cast || (language == .v && name[0].is_capital()) {
 			// MainLetter(x) is *always* a cast, as long as it is not `C.`
 			// TODO handle C.stat()
 			start_pos := p.tok.position()