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
#20933: At least one place maps 'test' to 'localhost'...fix test.

Discovery and patch by Wenzhu Man.  University of Waterloo apparently
maps the local name 'test' to localhost, which is in the bypass list,
causing the test to fail.  So change 'test' to a name unlikely to get
mapped to localhost.
Merge: #20933: At least one place maps 'test' to 'localhost'...fix test.
remove unused zero constants
only define zero constant when it is used
merge 3.3
avoid referencing past the bounds of an array
merge 3.3
remove runtime_library_dirs for _sqlite; it isn't needed
merge 3.3