go1.11beta2 changes require wasm_exec.js update

[steveoc64]

go1.11beta2 is out now, and its got a new wasm_exec.js under the ./misc/wasm directory in the src tree.

They have changed around how _resolveCallbackPromise() works .. so you need to replace your cp of wasm_exec.js with the newer one (if you want to not crash under beta2 that is)

Tested with the latest release, and it works great. Excellent stuff, this is huge fun to follow !