Latest v8 breakages from Node.js v16

[alexlamsl]

@kzc new raisins from nodejs/citgm#852 (comment)

UglifyJS/test/compress/classes.js

Lines 760 to 781 in 73a5643

	unused_await: {
	options = {
	inline: true,
	unused: true,
	}
	input: {
	var await = "PASS";
	(async function() {
	class A {
	static p = console.log(await);
	}
	})();
	}
	expect: {
	var await = "PASS";
	(async function() {
	(() => console.log(await))();
	})();
	}
	expect_stdout: true
	node_version: ">=12"
	}

 --- classes.js
     Running test [unused_await]
 !!! failed
 ---INPUT---
 {
     var await = "PASS";
     (async function() {
         class A {
             static p = console.log(await);
         }
     })();
 }
 ---EXPECTED ERROR---
 SyntaxError: Unexpected reserved word
 ---ACTUAL STDOUT---
 PASS

UglifyJS/test/compress/loops.js

Lines 831 to 841 in 6335b5f

	for_of: {
	input: {
	var async = [ "PASS", 42 ];
	async.p = "FAIL";
	for (async of (null, async))
	console.log(async);
	}
	expect_exact: 'var async=["PASS",42];async.p="FAIL";for(async of(null,async))console.log(async);'
	expect_stdout: true
	node_version: ">=0.12"
	}

 --- loops.js
     Running test [for_of]
 !!! failed running reminified input
 ---INPUT---
 {
     var async = [ "PASS", 42 ];
     async.p = "FAIL";
     for (async of (null, async)) console.log(async);
 }
 ---OPTIONS---
 {
     "ie8": true,
     "toplevel": true
 }
 ---OUTPUT---
 var o=["PASS",42];o.p="FAIL";for(o of o)console.log(o);
 ---EXPECTED ERROR---
 SyntaxError: The left-hand side of a for-of loop may not be 'async'.
 ---ACTUAL STDOUT---
 PASS
 42

[kzc]

Odd. It was unambiguous with token lookahead. The change is to prevent potential ambiguity with future spec changes.

https://docs.google.com/presentation/d/1POaK3AQxbdeDIq5M1RVjH1YIHe3fSxOCPPALTHIaLyo/edit#slide=id.g75ad152717_0_5

"Browsers disagree on what happens here"

[alexlamsl]

"Browsers disagree on what happens here"

Pardon my expression, but that is a sorry excuse for a specification.

Guess when the breakage does hit our CI, we'll update node_version then append to the list in README.md 🤷

[alexlamsl]

I guess ECMAScript specification is evolved by discovering bugs "features" on latest versions of v8.

[alexlamsl]

Addressed by #4857