Ability to list each item on Exports/Data Segments/Functions

[COFFEETALES]

It gives the possibility to list several contents in a decoded module.

Some examples of the use of the JS api:

const decodedModule = binaryen.parseText( my_wast_content );

for ( let i = 0, len = decodedModule.getNumExports() ; i !== len ; ++i )
{
    const ptr = decodedModule.getExportByIndex(i);
    const expInfo = binaryen.getExportInfo(ptr);

    console.log('export id: ' + i.toString(10));
    console.log('ptr: ' + ptr.toString(10));
    console.log('expName: ' + expInfo.name);
}

for ( let i = 0, len = decodedModule.getNumFunctions() ; i !== len ; ++i )
{
    const ptr = decodedModule.getFunctionByIndex(i);
    const funcInfo = binaryen.getFunctionInfo( ptr );

    console.log('function id: ' + i.toString(10));
    console.log('ptr: ' + ptr.toString(10));
    console.log(funcInfo);
}

for ( let i = 0, len = decodedModule.getNumMemorySegments() ; i !== len ; ++i )
{
    const segment = decodedModule.getMemorySegmentInfoByIndex(i);

    console.log('data segment id: ' + i.toString(10));
    console.log('byteOffset: ' + segment.byteOffset );
    console.log(new Uint32Array(segment.data)); // ArrayBuffer treated as Uint32
}

[tlively]

Small comments inline. Please also add tests in test/binaryen.js/kitchen-sink.js and test/example/c-api-kitchen-sink.c.

[tlively]

Looks great! Just one last readability comment on the tests and I think we're good to go.

[tlively]

Sorry, I noticed a few more C++ issues. This is the last of it for real now 👍

[dcodeIO]

While creating the respective bindings for AssemblyScript, I noticed that there is

int64_t BinaryenGetMemorySegmentByteOffset(BinaryenModuleRef module,
                                           BinaryenIndex id) {

returning an int64_t, which might be problematic in JS/Wasm contexts (potentially overflow a double or be illegal without BigInt integration). Mentioning since we are using a portable C binding in JS on our end, where there is no i64, so we can't use this API.

[kripken]

@dcodeIO The returned value will contain the lower 32 bits, though, so it should just work for you (with wasm32 for sure).

[tlively]

This is fixed by #2432.

[dcodeIO]

Thanks! 🎉

Being so cautious here because asc is intended to be compiled to both JS and Wasm interchangeably at some point and whenever i64 or BigInt (which we don't have a good story for yet) pop up, I become a little nervous :)