[compiler-rt] Don't use __libc_stack_end on ARM
Commit b684c1a50f70 ("Add a Symbolizer::GetEnvP() method that allows
symbolizer implementations to customise the environment of the
symbolizer binary.") exposed a latent ARM issue, and that broke
This coincided with breakage caused by my commit 5f5fb56c68e4
("[compiler-rt] Intercept the uname() function"), so I had to
The issue is that GetArgsAndEnv does not work on ARM: there glibc's
_start overwrites argc value stored at __libc_start_end, breaking the
existing argv/envp parsing logic.
Fix by inferring argc from argv.
Reviewers: eugenis, vitalybuka
Reviewed By: eugenis
Subscribers: dberris, kristof.beyls, danielkiss, #sanitizers, delcypher
Differential Revision: https://reviews.llvm.org/D77400