Make flipflop smartmatch against $_ instead of calling .Bool.
Merge branch 'smartmatch_flipflop' of https://github.com/peschwa/rakudo into nom
Make sure we can from/removed obsolete vars also
Put from/removed info on current Deprecations
Remove reference to obsolete $*OS

$*DISTRO.is-win is what we really wanted
Properly check compiler version

Should fix deprecation test errors on parrot and jvm
Bump up memory required to build rakudo-j

(2000 may be too high, but 1000 is definitely too low)
Speed up Bool.pick/roll
Stay in NQP land as much as possible

Good for another 15% performance increase
Mention Bool.pick/roll now 20x faster
Make .round (no parameters) about 3x as fast
De-pessimize Bool.pick(n)/roll(n)

It appears that literal value candidates are not yet optimized away, so having
them slows things down considerably.  So the (n) cases are now back to what
they were before I started all this (instead of worse).
Bring Supply up to spec wrt to s/more/emit/
Mention Supply.more is deprecated
Remove pessimation of .round($x)

Also using a literal param in MMD, which is still not optimized away.
Make IO::Socket|Proc::Async emit instead of more
Make sure signals emit rather than more
S/winner/earliest/ as by recent S17 spec change
winner.t is now earliest.t, as per spec change
Introduce faster IO::Path creator for abs paths