RFR(m): 8139233u1 add initial compact immutable collection implementations

[Stephen Colebourne]

On 9 May 2016 at 15:25, Remi Forax <forax at univ-mlv.fr> wrote:
>   CollSer implementation can be improved to avoid the ugly switch/case by replacing the constant list by an enum,

CollSer is modelled on JSR-310 code which uses an int. An enum would
be a huge overkill for this use case.

Stephen