Changes:

- Changed eval-err-contains-supercall-1.case to add a property access similar to eval-err-contains-supercall-2.case, without this property access eval-err-contains-supercall-1.case would be identical to eval-err-contains-supercall.case.
- Remove unnecessary "earlyerror" and "executionerror" template arguments when the value is already clear from the context.
- Fixed the description in eval-err-contains-supercall-2.case to refer to the correct early error rule.
- Fixed a copy-paste error in eval-err-contains-superproperty-1.case and eval-err-contains-superproperty-2.case.
- Split initializer-eval-super into initializer-eval-super-call and initializer-eval-super-property, because we actually need to test different behaviour for the super-call compared to the super-property case.
- Split initializer-eval into initializer-eval-arguments and initializer-eval-newtarget, because `arguments` and `new.target` are differently handled in class-fields.
- And fixed other copy-paste errors in the template files.

Fixes #1325

Fixes #1313

Fixes #1312

Fixes #1306

Only this test relied on $ERROR throwing a catchable Test262Error.

This change allows test environments to provide their on $ERROR function for better error reporting.

 fix typos in class field templates

Ref https://github.com/tc39/test262/commit/f1602088e6f1277d89548dfacf46dbaa0fb98154#commitcomment-25237057

classfields: eval early errors

BigInt: Add test for BigInt.prototype[Symbol.toStringTag]

Missing generators flags

BigInt64Array/BigUint64Array

BigInt bitshift operators

RegExp property escapes: test Extended_Pictographic

CONTRIBUTING.md: More detail about "features"

typeof fixups

tools/lint: install  PyYAML if not available

BigInt bitwise and, or, xor

DataView.prototype.getBigInt64 tests

Tests the fix for https://github.com/tc39/proposal-bigint/issues/92

CONTRIBUTING.md Fix mistake in test generation section

BigInt: BigInt .toString() returns only decimal digits, does not include BigIntLiteralSuffix