src/vs/platform/contextkey/common/contextkey.ts/expressionsAreEqualWithConstantSubstitution
export function expressionsAreEqualWithConstantSubstitution(a: ContextKeyExpression | null | undefined, b: ContextKeyExpression | null | undefined): boolean {
	const aExpr = a ? a.substituteConstants() : undefined;
	const bExpr = b ? b.substituteConstants() : undefined;
	if (!aExpr && !bExpr) {
		return true;
	}
	if (!aExpr || !bExpr) {
		return false;
	}
	return aExpr.equals(bExpr);
}