A constant defined in a function/method should be treated as
dynamic.
A class constant with a dynamic initializer should evaluate to
the value of its initializer at the time the constant was first
seen; so the optimization should be all or nothing - either
turn the class constant into a scalar, or leave it in its original
form.
This change is mostly for FB internal organizational reasons.
Building is not effected beyond the fact that the target now
lands in hphp/hhvm/hhvm rather than src/hhvm/hhvm.
mwilliams