win/tclWinChan.c Tcl_InitNotifier: Bug [2413550] Avoid reopening of serial channels which causes issues with Bluetooth virtual com. Patch by Rolf Schroedter.
merge 8.5
Changed position of flag evaluation as proposed by Phil Hoffman
Do not reopen a win serial channel for serial detection. There are issues with some Bluetooth virtual com. Fix bug [2413550], patch by Rolf Schroedter