Import test changes from V8

Merge pull request #1998 from test262-automation/javascriptcore-test262-automation-export-8e3c6d04

Import test changes from JavaScriptCore

[v8-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 44b1b245 targetRevisionAtLastExport: ae464533

[v8-test262-automation] Changes from https://github.com/v8/v8.git at sha 44b1b245 on Sat Dec 15 2018 19:17:33 GMT+0000 (Coordinated Universal Time)

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 2b233fa3c0 targetRevisionAtLastExport: 8e3c6d04

[javascriptcore-test262-automation] Changes from https://github.com/webkit/webkit.git at sha 2b233fa3c0 on Sat Dec 15 2018 19:14:38 GMT+0000 (Coordinated Universal Time)

https://github.com/tc39/proposal-intl-segmenter/pull/55

test: Ensure private methods are visible from all initializers

This makes v8's _monkeyYaml happy --- without it, the info block never ends, and we fail to parse the `features` key.

An explicit indentation marker isn't used because monkeyYaml doesn't supported it, and adding it might slightly slow things down.

Using PyYAML instead was considered, but after trying it, I don't think it looks viable. [simple test cases](https://gist.github.com/caitp/4a59a67f671907c11051a1b7bd5fdaae)

Import test changes from V8

Merge pull request #1991 from test262-automation/javascriptcore-test262-automation-export-cab19d71

Import test changes from JavaScriptCore

[v8-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 9583858e targetRevisionAtLastExport: d420adb9

[v8-test262-automation] Changes from https://github.com/v8/v8.git at sha 9583858e on Mon Dec 10 2018 19:17:52 GMT+0000 (Coordinated Universal Time)

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 205489c4f0 targetRevisionAtLastExport: cab19d71

Import test changes from V8

Merge pull request #1986 from test262-automation/javascriptcore-test262-automation-export-31e654a3

Import test changes from JavaScriptCore

- Changes associated with spec changes (tc39/proposal-string-matchall#41)
- Update spec comments
- Added test verifying error thrown when `regexp[Symbol.matchAll]` is not callable
- Added test verifying `ToString` is called on `receiver`

https://github.com/tc39/ecma262/pull/1340

[v8-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 4a395137 targetRevisionAtLastExport: 07b31310

[v8-test262-automation] Changes from https://github.com/v8/v8.git at sha 4a395137 on Tue Dec 04 2018 19:12:32 GMT+0000 (Coordinated Universal Time)

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 60ed1be8cd targetRevisionAtLastExport: 31e654a3

[javascriptcore-test262-automation] Changes from https://github.com/webkit/webkit.git at sha 60ed1be8cd on Tue Dec 04 2018 19:08:52 GMT+0000 (Coordinated Universal Time)

Import test changes from V8

Merge pull request #1979 from test262-automation/javascriptcore-test262-automation-export-0210918f1e

Import test changes from JavaScriptCore

[v8-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: cac6b037 targetRevisionAtLastExport: 4dc4cfd8

[v8-test262-automation] Changes from https://github.com/v8/v8.git at sha cac6b037 on Fri Nov 30 2018 19:08:50 GMT+0000 (Coordinated Universal Time)

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: e7f9d46220 targetRevisionAtLastExport: 0210918f1e

Eliminate some false positives