Remove some spurious blank lines

Formalize installation procedure

A few BigInt tests had a blank line in an inconvenient place which
breaks an old, possibly incorrect YAML parser used by V8's test262
test automation. The best fix is to deploy a new YAML parser, but
in the short term, this patch deletes the blank lines and lets
V8 understand the feature flags below. Related: #1370

Ensure that the linter's Python dependencies are satisfied in the
continuous integration environment.

Note that this is not currently necessary but only because the linter's
dependencies happen to align with those of the test generation tool. The
dependencies of the two tool should be satisfied explicitly in order to
promote isolation.

Split class fields tags

Class fields with the same name

Fixes #1355 

The tests are explicitly for bad hex chars at certain indexes, and that
rogue `%` was giving false positives.

The change is done in the following patch, where default options
have a null prototype. This matches what other Intl objects have.
https://github.com/tc39/proposal-intl-plural-rules/commit/1abe8af440fb47d888ace701e8a46559bdbe7b06

Added missing cases into BigIntConstructor with String parameters

Fix #1345

Originally discovered by Cait Potter (@caitp), reported in irc.mozilla.org#jslang

- Add tests for multiple public fields of the same name
- Reorganize fields default templates
- Add more tests for redeclaration of fields
- Remove non used template
- Add tests for computed property names in class fields definitions
- Minor test fixes

Thanks @andresaraujo for helping with the early review

* Accessing `ta[0]` throws a TypeError.

* Fix array indices starting at 0 and property references

* Fix classfields templates for properly checking static propnames.

* Generate tests

* `assert.equal` is not defined

* Add missing includes

* Generate tests

* typo s/Avalue/42/

* fix whitespace

* Add missing var for strict mode

* Expand generated class fields tests for forbidden computed property name values

Ref https://github.com/tc39/test262/pull/1339#issuecomment-342830243

* derived classes have access to private names in base classes, if private names are in scope

classfields: Tests for modified algorithms and Private Names

Add tests for setting/defining an element of a typed array to a value, where converting that value to the typed array element type detaches the buffer underlying the typed array. (#1336)

fixup: swap actual and expected in test/built-ins/Promise/prototype/finally/species-symbol.js (#1333)

classfields: add tests duplicate private fields and deleting private fields

classfields: add tests for privatename production and ASI