Previously, the cache recorder used a vector of sequencer pointers to
access Ruby objects. A recent commit updated the cache recorder to also
maintain a vector of GPUCoalescer pointers in order for GPUs to support
flushin. This added redundant code to the cache recorder. This commit
replaces the sequencer and GPUCoalescer vectors with a vector of
RubyPort pointers so that the code does not contain redundant lines
Change-Id: Id5da33fb870f17bb9daef816cc43c0bcd70a8706
08c1af1b16