Tests with custom a.out targets in their Makefile (i.e.
`TestBSDArchives.py`) bypass the standard Makefile.rules linking step
where `CODESIGN` is applied. This leaves the binary unsigned, causing
the process to get kill it on remote darwin devices.
This adds a codesigning step to the all target in Makefile.rules that
signs both $(EXE) and a.out if they exist. This ensures all test
binaries are signed regardless of how they were built.
rdar://173840592
Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>