[mingw only]setProgName():
  robustify by looking for the last '/' or '\\' in argv[0].
  My copy of 'gdb' likes to use a mixture of the two, which causes a
  fatal error when trying to debug libHSrts_p.a. Other process-invoking
  apps/shells might be equally wavering when it comes to the use of slashes.

Merge to STABLE.