Apparent 4 avail bits in SV flags

It looks to me, and others on #p5p that there are 4 unused bits in the 
flags for an SV.

The types take up 4 bits, but then the actual flags, like SVf_IOK, start 
at 0x100.  That apparently means bits  matching the mask 0xF0 are 
available.  Are we wrong?

• Apparent 4 avail bits in SV flags by Karl Williamson
• Re: Apparent 4 avail bits in SV flags by Father Chrysostomos
• Re: Apparent 4 avail bits in SV flags by bulk88
• Re: Apparent 4 avail bits in SV flags by Leon Timmermans
• Re: Apparent 4 avail bits in SV flags by Karl Williamson