support relative paths on Windows in dr_open_file()

From derek.br...@gmail.com on April 30, 2010 16:06:53

We could try to support relative paths by reading the cur dir from the PEB at process startup when there's much less chance of a race, and prepending it to dr_open_file() paths that look relative.

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=298