Make the devirtualization functions take the actual type we're
devirtualizing (or speculatively devirutalizing) to, in order to
simplify the handling of metatypes. Remove the ClassDecl parameter from
these functions since it can always be derived from this type.
These changes set things up for more forthcoming improvements to
metatype handling.
As part of this I've simplified the function that determines if a member
is known to be 'final'. My expectation is that this can be further
simplified by removing the type parameter as part of other improvements
to metatype handling.
Swift SVN r26165
It turns out we're already at a point where we can easily pass the same
data along to the devirtualization functions, and were already passing
some of it.
Swift SVN r26040
Redefine DevirtClassMethodInfo to carry fewer values in an effort to
reduce the coupling between these functions. Long term I expect this
structure to go away, but that is difficult to do without more
refactoring.
Swift SVN r26034
No functional change here, and this is not in its final form. This is
just cut/paste/tweak to split the code apart in a first reasonable form.
Swift SVN r25769
