Closes #20918: Added handling for exceptions during fallback output of logging exceptions.
Issue #20884: whatsnew: Frozen modules don't set __file__ anymore.
Added Doc/tools/ subdirs to .hgignore.
whatsnew: final edit pass.
Reverted change introduced in edb12dad7bf6.
cast negative numbers to size_t before shifting them (#20929)
don't do pointer arithmetic with signed numbers
merge 3.3
fix c89 declaration order
avoid referencing out-of-bounds memory
merge 3.3