workaround Unicode compatibility in testing

[alexlamsl]

No description provided.

[alexlamsl]

@kzc this should take care of the remaining issues in node-v4.2.1

The only other test with code points outside of the Basic Multilingual Plane does not call sandbox.run_code():

UglifyJS/test/mocha/string-literal.js

Lines 122 to 136 in 065c50e

	it("Should reject invalid code points in Unicode escape sequence", function() {
	[
	// A bit over the valid range
	'"\\u{110000}"',
	// 32-bit overflow resulting in "a"
	'"\\u{100000061}"',
	].forEach(function(test) {
	assert.throws(function() {
	UglifyJS.parse(test);
	}, function(e) {
	return e instanceof UglifyJS.JS_Parse_Error
	&& /^Invalid escape sequence: \\u{1/.test(e.message);
	}, test);
	});
	});

[kzc]

That does the trick. Both node-v4.2.1 test/compress.js unicode.js and node-v4.2.1 test/mocha.js pass without error.