Add script to convert from utf8 to internal (utf16) representation.

exec/load/utf8_utf16.js

+// $Id: utf8_cp437.js,v 1.6 2019/07/24 22:05:29 rswindell Exp $
+
+function utf8_utf16(uni)
+{
+	return uni.replace(/[\xc0-\xfd][\x80-\xbf]+/g, function(ch) {
+		var i;
+		var uc = ch.charCodeAt(0);
+		for (i=7; i>0; i--) {
+			if ((uc & 1<<i) == 0)
+				break;
+			uc &= ~(1<<i);
+		}
+		for (i=1; i<ch.length; i++) {
+			uc <<= 6;
+			uc |= ch.charCodeAt(i) & 0x3f;
+		}
+
+		return String.fromCharCode(uc);
+	});
+}