Fix SmallPtrSet::iterator behaviour and creation ReverseIterate is true.
- Any function that creates an iterator now uses
SmallPtrSet::makeIterator, which creates an iterator that
dereferences to the given pointer.
- In reverse-iterate mode, initialze iterator::End with "CurArray"
instead of EndPointer.
- In reverse-iterate mode, the current node is iterator::Buffer[-1].
iterator::operator* and SmallPtrSet::makeIterator are the only ones
that need to know.
- Fix the assertions for reverse-iterate mode.
This fixes the tests Danny B added in r297182, and adds a couple of
others to confirm that dereferencing does the right thing, regardless of
how the iterator was found, and that iteration works correctly from each
return from find.
llvm-svn: 297234
1e4b2c7632