update minimum CI version to match actual required minimum version

ignore .var/

Add support for codegen xhp classes (hhvm#138)

* Add support for codegen xhp classes
Adds xhp attribute codegen to traits and classes.
No error is thrown when attributes are added to non-xhp classes.
This syntax is valid, but not useful in the current class.
Inheritance maybe?

* Fix broken copy paste

* Compatibility with older hsl versions

* Whitespace lint

* Update xhp attribute doc

I copy pasted property and did not touch up the doc well enough.

replace $GLOBALS with \HH\global_get()

Stop using files with pseudomains

hhvm-autoload generates several alternative files, which
functioned as migration aids from composer; migrate to one
of the newer ones, as the older ones are becoming
invalid/unusable as HHVM development continues.

Replace PHP arrays with varray and darray

Grepped for \barray\b , fixed all call sites.

No log spew on test run

Bump nokogiri from 1.10.4 to 1.10.8 in /docs (hhvm#126)

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.4 to 1.10.8.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.10.4...v1.10.8)

Signed-off-by: dependabot[bot] <[email protected]>

Support `disallow_array_literal` (hhvm#119)

* Support `disallow_array_literal`

* Enable strict options that introduce test failures

* Require HHVM 4.25 for HHI support of array_literal

* Test on composer.json version of hhvm

fix composer.json

also support fbexpect 2.6.1