[sanitizer_common] child_stdin_fd_ should only be set on posix_spawn path (#171508)

#170809 added the child_stdin_fd_ field on SymbolizerProcess to allow
the parent process to hold on to the read in of the child's stdin pipe.
This was to avoid SIGPIPE.

However, the `StartSubprocess` path still closes the stdin fd in the
parent here:

https://github.com/llvm/llvm-project/blob/7f5ed91684c808444ede24eb01ad9af73b5806e5/compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp#L525-L535

This could cause a double-close of this fd (problematic in the case of
fd reuse).

This moves the `child_stdin_fd_` field to only be initialized on the
posix_spawn path. This should ensure #170809 only truly affects Darwin.

0 files changed, 0 insertions, 0 deletions