module.exports assignment in a JavaScript file cannot be imported with ES6 syntax

[billti]

See commented out failing test in this pull request.

I've spent a while in the debugger on this, and the root cause appears to be how the export= SymbolObject is constructed in the source file's symbol.exports property in a JavaScript module source file versus a TypeScript module source file. This causes resolveESModuleSymbol to return undefined.

Being it applies only to this specific construct (i.e. assignments to exports. work with es6 imports, or importing with var <id> = require(...) syntax works), its not a total blocker. But would be good to fix ASAP, especially as the error is rather unattractive.

[Arnavion]

If you do do this, please consider stripping the () and new() members from the import binding to be compliant with ES6 (option 2 in #6809)

[billti]

Verified this is working in the current bits in 'master'.