ECMAScript proposal updates at 2018-01

The changes of proposal’s status @ 62nd meeting of Ecma TC39

New Proposals

Proposal	Stage
`{BigInt,Number}.fromString`	1
`Math.seededRandoms()`	1
`Function.prototype.toString()` censorship	1
Top-level `await`	1
Maximally minimal mixins	1

Proposal	From	To
RegExp named capture groups	3	4
Rest/Spread Properties	3	4
RegExp Lookbehind Assertions	3	4
RegExp Unicode Property Escapes	3	4
`Promise.prototype.finally`	3	4
Asynchronous Iteration	3	4
JSON superset	2	3
`String.prototype.{trimStart,trimEnd}`	2	3
`String.prototype.matchAll`	2	3
`Symbol.prototype.description`	1	2