Remove uneeded sourcemap directive from earcut.

[mramato]

The sourcemap directive at the bottom of earcut was giving several users problems. The simple solution is to just remove it.

Closes #4097
Fixes #4094

[chris-cooper]

This fix doesn't work for me. This repo should repro the error, and you can hack on earcut in node_modules/cesium to test : https://github.com/PropellerAero/cesium-webpack . I found the warning remains with your fix, but goes away with #4097.

[mramato]

Have you brought up the issue with the webpack team? If the sourcemap isn't the problem and instead it's the UMD wrapper, it sounds like this may be triggering a bug on the webpack side of things. Another option is that the bug is in the UMB wrapper itself and it's a bug in the earcut build, in which case you might want to open an issue with minimmal reproduction with the earcut folks.

I don't have a problem working around it with #4097 in the meantime, but it would be nice to determine the root cause and have that fixed in the proper repository

[chris-cooper]

It looks like there's already this webpack issue. One of the ideas mentioned is to pull module source code into your webpack built app rather than pre-built libraries. Earcut on NPM already publishes the source under src/earcut.js but it's not AMD. The change in #4097 is just providing the AMD boilerplate.

[mramato]

Thanks, I'll merge your other issue and link to this PR for more info.