Apparently, breakpoints and watchpoints are practically disabled if
run with OPcache JIT under Windows, so we mark the affected tests as
xfail in that case for the time being.
This allows reading the initial script file from stdin instead of being forced to put the script into a file in order to run it with phpdbg.
Especially important for programmatic execution of phpdbg.
Also adding tests/include_once.phpt and tests/set_exception_handler.phpt as I seem to have forgotten to git add them sometime long ago...