Async binding & destructuring issues

[KFlash]

After experimenting with Esprima I come across a lot of binding & destructuring issues. Cases that actually should fail, but doesn't.

I used the ASTExplorer to verify this.

Steps to reproduce

 // parenthesized

esprima.parse('async ((x, y, z)) => 0 ')

// nested
esprima.parse('async(async(async(async(async(async())))))')

 // others
esprima.parse('async(a)(s)(y)(n)(c)')
esprima.parse('async (async ()  => a)  => a')
esprima.parse('async(async() () => {})(async() () => {})(y)(n)(c)')
esprima.parse('async().foo13 () => 1')
esprima.parse('async(async() () => {})(async() () => {})(async() () => {})(async() () => {})(async() () => {})')
esprima.parse('async().foo13 () => 1')
esprima.parse('async()(async() => {})')

Expected output

This cases should all throw an syntax error

Actual output

Parses as normal, and doesn't throw any errors

Relevant references

V8, Acorn, Test262 among others