Apply the MALLOC_ZERO_WORKS fixup to tor_realloc as well.

Also, make MALLOC_ZERO_WORKS never get applied when clang analyzer is
running.  This should make the clangalyzer a little happier.
Explicitly initialize addresses in tor_ersatz_socketpair

This should stop a false positive from the clangalyzer.
Add an assertion to read_file_to_str_until_eof

The clangalyzer doesn't believe our math here.  I'm pretty sure our
math is right.  Also, add some unit tests.
Add more assertions to esc_for_log to please the clangalyzer.
Don't include a backtrace test for dereferencing 0 under analyzers

They hate this.
Use real pointers in unit tests, not (void*)101 etc

The clangalyzer hates (void*)101 etc
Make iter for DECLARE_TYPED_DIGESTMAP_FNS be a pointer.

This fixes a clangalyzer warning, and makes our C slightly better C.
Fix more (void*)11 warnings in the tests