Fix bug in test suite on systems that use '\' as a path separator (Windows)
Fix bug in test suite on systems that use '\' as a path separator (Windows)

test_suite/main.lua
   One of the tests involves generating a script file on-the-fly and
executing it.  This script file includes a filename that may contain
a path.  On Windows systems, the backslashes in the filename are not
escaped, resulting in a test failure.

Stevie-O/SharpLua,Stevie-O/SharpLua,Stevie-O/SharpLua