This is sort of a long overdue change from the investigation in #29293
and #37477. The released binaries of rustc don't have debug information and so
don't actively suffer this problem but this can hit local development of rustc
and also larger programs compiled against libstd generating backtraces.
The main purpose of the mmap allocator in libacktrace is to be usable from a
signal handler, but we don't do that, so the normal allocator using malloc/free
should work well for us.
This updates the vendor'd libbacktrace source to tpick up
gcc-mirror/gcc@047a1c2f which is a soundness fix for when a backtrace is
generated on executables that do not have debug information.
These should probably be submitted upstream. They're inevitably going to
complicate merges, and because they're non-functional changes this just
isn't worth our time.
Remove leading newlines; replace lines containing only whitespace with empty lines; replace multiple trailing newlines with a single newline; remove trailing whitespace in lines
Fix formatting
Remove unused imports
Refactor
Fix msvc build
Fix line lengths
Formatting
Enable backtrace tests
Fix using directive on mac
pwd info
Work-around buildbot PWD bug, and fix libbacktrace configuration
Use alternative to `env -u` which is not supported on bitrig
Disable tests on 32-bit windows gnu
