Write execution logs to a named log file (#409)

This patch adds a --log argument to spike. If not given, the behaviour
is unchanged: messages logging execution of instructions and (if
commit logging is enabled) commits go to stderr.

If --log=P is given, Spike now writes these messages to a log file at
the path P. This is nice, because they are no longer tangled up with
other errors and warnings.

The code is mostly plumbing: passing a FILE* object through to the
functions that were using stderr. I've written a simple "log_file_t"
class, which opens a log file if necessary and yields it or stderr.

0 files changed, 0 insertions, 0 deletions