Fix parsing of IIAFE `(async function (){ }())` with acorn v3.

Fix parsing of IIAFE (async function (){ }()) with acorn v3.

Add tests.

Correct parsing of `class Foo { static get() {...} }`

1.1.5

Add tests for static class getters/methods

Disambiguate async, get and set when defining object properties

Fix disambiguation of async, get and set tokens (and add tests) when defining object properties

Update for acorn v4. Also works with v2 and v3

Update to work with acorn v4, if present. Note that async and await are fully parsed by acorn v4. The use cases for the plugin are:

• With acorn v4, to use the compiler options which are enable specific parsing modes
• When the installed version of acorn is unknown (for example if passed from another tool such as webpack)

Correctly parse `async(()=>0)`

Correctly parse async(()=>0) as a call to the Identifer 'async', not a failed attempt to define an async arrow.

Implement non-standard "range" property on async nodes

Required by tools such as Webpack

Fix issue parsing async methods in classes and object literals which (incorrectly) required the `awaitAnywhere` option

(incorrectly) required the `awaitAnywhere` option

Closes https://github.com/MatAtBread/acorn-es7-plugin/issues/12

Parse comments correctly. Add option `inAsyncFunction`

Correctly parse comments between async and function.
Implement the option inAsyncFunction

Correctly parse `export async function name(){...}`

Correctly parse the statement export async function name(){...} as async function name(){...} is a valid named declaration.

Return the original acorn object

Update to return the original acorn object. See #4

This is minor update with no functional changes, just a convenience method.