instead of cloning and RAUWing it.
- Make AbstractTypeUser a friend of Value so that it can offer
its subclasses a way to update a Value's type in place. This
is better than a universally visible setType method on Value,
and it's sufficient for the immediate need.
- Eliminate the constant "convert" functions. This eliminates a
lot of logic duplication, and fixes a complicated bug where a
constant can't actually be cloned during the type refinement
process because some of the types that its folder needs are
half-destroyed, being in the middle of refinement themselves.
- Move the getValType functions from being static overloaded
functions in Constants.cpp to be members of class template
specializations in ConstantsContext.h. This means that the
code ends up getting instantiated twice, however it also
makes it possible to eliminate all "convert" functions, so
it's not a big net code size increase. And if desired, the
duplicate instantiations could be eliminated with some
reorganization.
llvm-svn: 81861
