Parsing yield + dynamicImport

[hzoo]

Ref babel/babel-preset-env#168

I believe preset-env -> async-to-gen and it fails to parse

Seems like this doesn't parse: http://astexplorer.net/#/gist/d793e984f4ccfe0ca80c3760490c2fc2/62f92b3ed7628599ad98e884a7e3c1ee25344798

function* a() {
  yield import('http');
}

@kesne

[kesne]

This is also tracked in webpack, for the acorn plugin that's here: https://github.com/kesne/acorn-dynamic-import

Probably should knock both out at once, most people using import() in webpack use babel-eslint, so having them match would be 💯

[hzoo]

Also made webpack/webpack#4308 btw

On that note, should probably figure out how to make babel-eslint simpler now that we have estree again

[kesne]

Webpack will be fixed with this: kesne/acorn-dynamic-import#5