cleanup m_sharedPredTransformSkip[]

NEW_CALCRECON macro is TODO mark for asm experts, to optimize register assignment.

--HG--
extra : rebase_source : 3bd0f862dac48106ef29d0220f5cfa4e6cf9800c
Removed Encoder* as member of DPB and replaced it with field m_bOpenGOP

Also added int bframes to Lowres since only param->bframes is passed to its
methods thus eliminating one of DPB's uses of Encoder*

--HG--
extra : rebase_source : 33757d14fa6e295ee1aa656f6efac6e5a6604016
Replaced Encoder* with x265_param* as member of several classes

Replaced Encoder* with x265_param* as member of TEncCu, framefilter,
ratecontrol, CostEstimate and Lookahead Added m_CUTransquantBypassFlagValue to
TEncCu since it's part of Encoder and not x265_param framefilter's processRow
and processRowPost needed Encoder* to run Encoder::signalReconRowCompleted

--HG--
extra : rebase_source : 99a6ed6ca26c60a6f838fc48cb24b3654d952e94
TEncCu: nits, no logic change
me: skip TMVP merge candidates that are beyond vertical search range

Because of frame parallelism, pixels more than search range below coincident
may not be available in references.  Sometimes these merge candidates happened
to be the best cost, resulting in hash mismatches.

Because xMergeEstimation() can now return with no valid merge modes, the caller
must deal with the potential of no merge mode. predInterSearch() is sometimes
called to only measure merge modes (skipping ME for AMP partitions for some
presets), so now predInterSearch() can also possibly exit without generating
a valid prediction.
TEncSearch: remove confusing default arguments from predInterSearch()

And completely remove bLuma which was always true
TEncSearch: remove default argument from encodeResAndCalcRdInterCU()
TEncCu: disable TMVP range check if frame threading disabled, code style nits

--HG--
extra : amend_source : 2fc2f7defc7e70a185156587314fd2cf0bb83ffe