Binary AST is stage 1, per 2017.07 TC39.

Fixes #65

README.md

@@ -57,6 +57,7 @@ This list contains only stage 1 proposals and higher that have not yet been with
 |   | change Number.parseInt/parseFloat to not coerce null/undefined/NaN (repo link TBD) | Brendan Eich                  | 1 |
 |   | [Array.prototype.flat{Map,ten}][flat]                            | Brian Terlson, Michael Ficarra                  | 1 |
 |   | [Throw expressions][throw-expressions]                           | Rob Buckton                                     | 1 |
+|   | [Binary AST][binary-ast]                                         | Shu-yu Guo                                      | 1 |
 
 🚀 means the champion thinks it's ready to advance but has not yet presented to the committee.
 
@@ -118,3 +119,4 @@ Note that as part of the onboarding process your repository name may be normaliz
 [symbol-description]: https://github.com/tc39/proposal-Symbol-description
 [flat]: https://github.com/tc39/proposal-flatMap
 [throw-expressions]: https://github.com/rbuckton/proposal-throw-expressions
+[binary-ast]: https://github.com/syg/ecmascript-binary-ast