Add platform-specific interface to log information about the current
process.
On Windows, this interface is used to indicate whether the git process
is running under a debugger and list names of the process ancestors.
Information for other platforms is left for a future effort.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
