After conversations in #1215, we need to catch up with the code that was previously
produced before we set the features flags requirements.

This proposal was started in https://github.com/tc39/ecma402/issues/122,
and specified in https://github.com/tc39/ecma402/pull/148

Fix BigInt less-than operator test when both operands have the same MV

More fixes for bigint and MIN_VALUE comparisons

Ref https://github.com/tc39/test262/pull/1198#discussion_r137060514

Because Proxies no longer allow to return duplicate property keys.

Misc. class fields fixes

Incorrect $DONE handlers which led to calling $DONE twice
- async-generators/yield-promise-reject-next-yield-star-async-iterator.case
- dstr-assignment-for-await/array-elem-trlg-iter-rest-nrml-close-skip.case

$DONE handler not called at all:
- dstr-assignment-for-await/array-elem-put-const.case
- dstr-assignment-for-await/array-elem-trlg-iter-elision-iter-nrml-close-null.case

Incorrect assumed execution sequence in IteratorDestructuringAssignmentEvaluation:
- dstr-assignment-for-await/array-elem-iter-rtrn-close-null.case