ADT: Never allocate nodes in iplist<> and ilist<>

Remove createNode() and any API that depending on it, and add
HasCreateNode to the list of checks for HasObsoleteCustomizations.  Now
an ilist *never* allocates (this was already true for iplist).

This factors out all the differences between iplist and ilist.  I'll aim
to rename both to "owning_ilist" eventually, to call out the interesting
(not exactly intrusive) ownership semantics.  In the meantime, I've left
both names around to reduce code churn.

One of the deleted APIs is the ilist copy constructor.  I've lifted up
and tested iplist::cloneFrom (ala simple_ilist::cloneFrom) as a
replacement.

Users of ilist<> and iplist<> that want the list to allocate nodes have
a few options:
- use std::list;
- use AllocatorList or BumpPtrList (or build a similarly trivial list);
- use cloneFrom (which is explicit at the call site); or
- allocate at the call site.

See r280573, r281177, r281181, and r281182 for examples of what to do if
you're updating out-of-tree code.

llvm-svn: 281184

0 files changed, 0 insertions, 0 deletions