Remove Babel object spread transformation

[nolanlawson]

Remove this transformation:

lwc/packages/@lwc/compiler/src/transformers/javascript.ts

Line 51 in d00e588

babelObjectRestSpreadPlugin,

This was needed for compat with older browsers, but is no longer needed.

Unfortunately, removing it would be an observable change; here is a list of bugs with the Babel implementation.

I tested a couple of them and verified that they still reproduce a difference between native V8 and Babel.

[nolanlawson]

This repro in particular still seems to show a difference between Babel and native: babel/babel#10743 (REPL)

[git2gus]

This issue has been linked to a new work item: W-13653003