Use unique location catalogs to encode Dex register maps.

- For each CodeInfo object (i.e. for each method), compute a
  variable index size location catalog  of unique Dex
  register locations.  In Dex register maps, instead of
  storing the actual location of a (live) Dex register,
  store the index of the location catalog entry containing
  that Dex register location.
- Adjust art::StackMapStream,
  art::StackVisitor::GetVRegFromOptimizedCode, and
- Add LoadBits and StoreBits methods to art::MemoryRegion
  to load and store a block of adjacent bits in a memory
- Update compiler/optimizing/
- Remove the default value for parameter EmptyFn of
  art::HashMap.  This default value did not seem to make
  sense, as it would create an "empty function" for type Key
  by default, whereas art::HashMap expects an "empty
  function" for type std::pair<Key, Value>.

Change-Id: Id9e49d7756c253ce41c36630cd832208d06c2e28
8 files changed