Update to Go 1.16.3's libexec/misc/wasm/wasm_exec.js

[turbolent]

Description

As we are now building the WebAssembly binaries for the parser and language server with Go 1.16, also update the run-time file.

This is a stripped version of the distributed libexec/misc/wasm/wasm_exec.js.

The new version contains whitespace changes, to see the real diff, disable whitespace changes in GitHub.

---

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[SupunS]

LGTM!