v4.2.2: support `dynamic` and coercing scientific notation with negative exponents (e.g. `3e-1`) to floats

empty commit to trigger CI

v4.2.1: support HHVM 4.117

Requires HHVM 4.115 or newer.

v4.2.0: support current nightly builds

This version:

• adds support for current nightly builds of HHVM, and is expected to support HHVM 4.88
• requires HHVM 4.80 or newer

4.1.2: support HHVM 4.71+

• replace all is_array() calls

4.1.1: support recent HHVM releases

• requires HHVM 4.64
• migrate array type annotations to varray or darray (required since HHVM 4.68)
• avoids a warning raised when using TypeSpec\enum in HHVM 4.68+

v4.1.0: support and require HHVM 4.63, array changes

This release:

• requires HHVM 4.63
• improves varray_or_darray() handling to return varrays in more cases, such as when coercing from a vec, instead of all coercions resulting in a darray; this is as 4.63 considers varray and darray to be distinct types
• removes PHP array support; it's not practical to support these on HHVM 4.63, and array() literals will shortly be removed from the language

4.0.0: remove support for dict-like-`array` and vec-like-`array`

Use the explicit darray or varray conversions instead.

• Reified or type-structure-based operations will now explicitly return a darray or varray instead of a PHP array.
• Untyped arrays will now be considered varray_or_darray<mixed>

Add `TypeSpec\of<reify T>()`

v3.7.3

remove new public type structure functions

Support `varray<T>`, `darray<Tk, Tv>`, `varray_or_darray<T>` in TypeSpec and type structure/reified assertions/coercions

This release adds:

• TypeSpec\varray()
• TypeSpec\darray()
• TypeSpec\varray_or_darray()
• Support for these types to TypeAssert\matches_type_structure() and TypeAssert\matches<reify T>(), and the corresponding coercion functions

Add `TypeSpec::toString()`, small improvements

This release:

• adds TypeSpec::toString(), which is intended to return the type as valid code - e.g. TypeSpec\string()->toString() returns 'string'
• makes Hack Collection coercions return the original value if the original value is valid, instead of returning a new object with the same elements
• improved and more performant error traces for Hack Collections