There are have been a few issues around people using case sensitive file systems
what Xcode/clang does when looking at the paths. In attempts to solve one set of
warnings, new warnings/errors happened in different setup. So, to hopefully put
these problem away for got, move the WKTs to be at the same level as the other
headers.
- Revert "Override CocoaPods module to lowercase (#6464)"
This reverts commit 479ba8226b.
- Move WKTs to the objectivec directory and make the old headers shim back to
the new locations.
- Update objectivec/generate_well_known_types.sh to check them one at a time
and to deal with the new locations for them.
Fixes#6803
To ensure all headers aren't dependent on other things being imported
before/after them, make a source that just imports each header and add
it to the unittesting target, that way we ensure it can be included on
its own with ordering issues.
Also do this testing with a few generated headers that aren't part of
the library to help ensure the different generated imports needed are
complete.
