gcc11: port is deactivating libgcc10, resulting in broken dependent ports

[mascguy (Christopher Nielsen)]

When updating ports today, I notice that libgcc10 was deactivated, despite a number of ports having a lib or runtime dependency on that port.

Reviewing new port gcc11, it looks like it's occurring there:

    pre-activate {
        if {![catch {set installed [lindex [registry_active libgcc10] 0]}]} {
            # Extract the epoch of the installed libgcc9
            set _epoch [lindex $installed 5]
            # If < 3 need to deactivate
            if {[vercmp $_epoch 6] < 0} {
                registry_deactivate_composite libgcc10 "" [list ports_nodepcheck 1]
            }