PreTransRecordTrees are likely optimizable.
Fix #1153: Inlineable classes break with dependent fields.
Allow aliasing to cross the inlineable class constructor barrier.

Basically, this allows to keep information about constants or
aliasing assigned to fields of an inlineable class, for use with
the instance returned by the constructor.
Lift the restriction on aliasing of InlineableClassBeingConstructed.

The only problem is if it is aliased to a field of itself. Otherwise,
scoping rules will prevent any bad thing from happening.
Merge pull request #1152 from sjrd/improve-inlineable-classes

Improve inlineable classes