entropy(9): Merge entropy_consolidate, entropy_consolidate_sig.

entropy_consolidate can already be interrupted by a signal -- it just
doesn't tell the caller this happened. So make it return the error
code, and delete entropy_consolidate_sig.

NOTE: This changes the semantics of an existing symbol, so it can't
be pulled up. (It might in principle be ABI-compatible because the
old symbol returned void and the new one returns int, so the caller
can just ignore the return value register in most if not all ABIs,
but I organized the relevant changes so we can pull up bug fixes
without thinking about this.) This is just tidying the kernel API
after all the previous fixes which can be pulled up.

PR kern/58646: /dev/random, kern.entropy.*: signal bugs

acpivmgenid(4): Reset and gather entropy on VM clone notification.

PR kern/58632: getentropy(2) and arc4random(3) do not reseed on VM
fork

acpivmgenid(4): New driver for virtual machine generation ID.

Added to amd64/ALL and i386/ALL kernel configurations, and made
available as a loadable module acpivmgenid.kmod on x86, for now.

TBD: Add to all ACPI-supporting GENERIC kernels.

PR kern/58632: getentropy(2) and arc4random(3) do not reseed on VM
fork

entropy(9): Merge entropy_consolidate, entropy_consolidate_sig.

entropy_consolidate can already be interrupted by a signal -- it just
doesn't tell the caller this happened. So make it return the error
code, and delete entropy_consolidate_sig.

NOTE: This changes the semantics of an existing symbol, so it can't
be pulled up. (It might in principle be ABI-compatible because the
old symbol returned void and the new one returns int, so the caller
can just ignore the return value register in most if not all ABIs,
but I organized the relevant changes so we can pull up bug fixes
without thinking about this.) This is just tidying the kernel API
after all the previous fixes which can be pulled up.

PR kern/58646: /dev/random, kern.entropy.*: signal bugs

acpivmgenid(4): Reset and gather entropy on VM clone notification.

PR kern/58632: getentropy(2) and arc4random(3) do not reseed on VM
fork

acpivmgenid(4): New driver for virtual machine generation ID.

Added to amd64/ALL and i386/ALL kernel configurations, and made
available as a loadable module acpivmgenid.kmod on x86, for now.

TBD: Add to all ACPI-supporting GENERIC kernels.

PR kern/58632: getentropy(2) and arc4random(3) do not reseed on VM
fork