swift234

Change FuncDecl/CtorDecl/DTorDecl/ClosureExpr constructors to
automatically reparent VarDecls in their arg/body patterns and
GenericParameters to themselves.  These all have to be created
before the actual context decl is created and then reparented,
so we might as well have the reparenting be done by the decl
itself.  This lets us take out some setDeclContext reparenting
loops from around the parser.  

I'm sure that there are a lot more places they can be removed
from as well.

NFC.


Swift SVN r13701