Pre-format a command to be executed on a fatal error to run 'dumper'
(using an absolute path).
Factor out executing a pre-formatted command, so we can use that for
invoking the JIT debugger in try_to_debug() (if error_start is present
in the CYGWIN env var) and to invoke dumper when a fatal error occurs.
On a fatal error, if the core file size limit is greater than 1MB,
invoke dumper to write a core dump. Otherwise, if that limit is greater
than 0, write a .stackdump file, as previously.
Adjust and clarify the associated documentation.
Also: Fix so that the error_start JIT debugger is now invoked, even when
ulimit -c is zero.
Also: Fix uses of console_printf() inside exec_prepared_command(). It's
output is written via the Windows console device, so needs to use
Windows-style line endings.
Also: consistently return non-zero from try_to_debug() if we debugged.
Future work: Truncate or remove the file written, if it exceeds the
maximum size set by the ulimit.
Future work: Using the words "fatal error" could probably be improved
on. This means exiting on one of the "certain signals whose default
action is to cause the process to terminate and produce a core dump
file".
91457377d6