:lang with empty expression list parsed incorrectly

[shagkur]

An incorrectly empty lang function type pseudo class like:

:lang() {
	color: black;
}

is parsed incorrectly (should probably even dropped) to this:
:lang( { color:black; }

[phax]

Documentation: https://developer.mozilla.org/en-US/docs/Web/CSS/:lang

[phax]

Part of 6.4.1

[phax]

(I don't want to add specific rules to all pseudo classes, except where specific syntax requirements are provided)