Ignore weak external symbols in clang coverage builds using check-for-weak-vtables-and-externals.
It turns out that -exported_symbol and -unexported_symbol can't be used together when linking:
ld: can't use -unexported_symbol and -exported_symbol
clang: error: linker command failed with exit code 1 (use -v to see invocation)
So go back to the solution from Bug 226562 (effectively reverting the change for Bug 226684).
Created attachment 433757 [details]
Note that the libwebrtc project was the first project failing with a coverage build before this change.
Committed r280021 (239763@main): <https://commits.webkit.org/239763@main>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 433757 [details].