parser: use parallel only on macos for now

vlib/v/parser/parser.v

@@ -171,6 +171,7 @@ fn (mut q Queue) run() {
 
 pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, global_scope &ast.Scope) []ast.File {
 	// println('nr_cpus= $nr_cpus')
+	$if macos {
 		if pref.is_parallel && paths[0].contains('/array.v') {
 			println('\n\n\nparse_files() nr_files=$paths.len')
 			println(paths)
@@ -190,6 +191,7 @@ pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, g
 			println('all done')
 			return q.parsed_ast_files
 		}
+	}
 	// ///////////////
 	mut files := []ast.File{}
 	for path in paths {

vlib/v/table/table.v

@@ -15,7 +15,7 @@ pub mut:
 	modules       []string // List of all modules registered by the application
 	cflags        []cflag.CFlag
 	redefined_fns []string
-	fn_gen_types  map[string][]Type
+	fn_gen_types  map[string][]Type // for generic functions
 }
 
 pub struct Fn {