vlib: add toml module + tests (#11964)

vlib/toml/util/util.v

@@ -0,0 +1,14 @@
+// Copyright (c) 2021 Lars Pontoppidan. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module util
+
+[inline]
+pub fn is_key_char(c byte) bool {
+	return (c >= `a` && c <= `z`) || (c >= `A` && c <= `Z`) // || c == `_`  || c == `-` <- these are identified when tokenizing
+}
+
+[if trace_toml ?]
+pub fn printdbg(id string, message string) {
+	eprintln(id + ' ' + message)
+}