fix various uses of generated names

This makes the entire std++ build with name mangling on Coq master.

added 2 commits

• 03304222 - fix various uses of generated names
• c00f91dc - enable name mangling

Compare with previous version

changed the description

Closing in favor of !182 (merged).

closed

What's the difference between the two MRs?

The other one also enables CI to check for generated names. :) That's why I had to change the branch name, and thus open a new MR. This also required a change in the telescope test.

Plus there was one more change needed in sorting.v.