(Patch Set 1 is identical to r37716; Patch Set 2 renames some typedefs to avoid confusing MSVC)
Highly customizable to support various internal uses as well as the basis for user-level classes.
Use in Library's resolved names cache.
Next step is to add new instance classes for the user-level maps/sets (akin to GrowableObjectArray).
TBR=asiva@google.com
Review URL: https://codereview.chromium.org//348313005
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@37800 260f80e4-7a28-3924-810f-c04153c831b5