* Add new tests to observe required leading line terminator

Ref #2095

Fix #2049

Test cases for async function and async generator edge-cases

https://github.com/mathiasbynens/unicode-property-escapes-tests/commit/1cfedb79bb971f6bccd77442cbf7fed9852a0aa0
https://github.com/tc39/ecma262/issues/1467
https://github.com/tc39/ecma262/pull/1468

Issue: tc39/ecma262#1461
PR: tc39/ecma262#1470

Update parseTestRecord to support hashbang tests

Add lint check for leading empty lines in description and info blocks

Fix #2034
Ref #1997

Spec link:

  https://tc39.github.io/proposal-bigint/#sec-serializejsonproperty

Thanks to André Bargull for the test:

  https://bugzilla.mozilla.org/show_bug.cgi?id=1528784

Per  https://tc39.github.io/ecma402/#sec-canonicalizelanguagetag
6.2.3 CanonicalizeLanguageTag ( locale )
The CanonicalizeLanguageTag abstract operation returns the canonical and case-regularized form of the locale argument (which must be a String value that is a structurally valid Unicode BCP 47 Locale Identifier as verified by the IsStructurallyValidLanguageTag abstract operation). A conforming implementation shall take the steps specified in the “BCP 47 Language Tag to Unicode BCP 47 Locale Identifier” algorithm, from Unicode Technical Standard #35 LDML § 3.3.1 BCP 47 Language Tag Conversion.

And
http://unicode.org/reports/tr35/#BCP_47_Language_Tag_Conversion
"
2. If the BCP 47 primary language subtag matches the type attribute of a languageAlias element in Supplemental Data, replace the language subtag with the replacement value.
If there are additional subtags in the replacement value, add them to the result, but only if there is no corresponding subtag already in the tag.
"
and
https://www.unicode.org/repos/cldr/trunk/common/supplemental/supplementalMetadata.xml
...
<languageAlias type="aar" replacement="aa" reason="overlong"/>
 <!--  [Afar]  -->
...
<languageAlias type="ces" replacement="cs" reason="overlong"/>
 <!--  [Czech]  -->
...
<languageAlias type="heb" replacement="he" reason="overlong"/>
 <!--  [Hebrew]  -->

get all the test data from constructor-non-iana-canon.js

Split from intl402/Locale/constructor-non-iana-canon.js

Remove all the assertion of result of getCanonicalLocales from Locale directory
and put them under Intl/getCanonicalLocales directory.

- indirect eval
- files renaming
- space after comma