* CHERRY_PICK 18941, 18860: TRT fp16 support.

test=release/1.5

* CHERRY_PICK 19213: Fix BUG: Mask RCNN inference diff When using AnalysisPredictor.
    1. fix affine channel fuse pass.
    2. fix condition block op.
    3. fix merge lod tensor op bug.
    4. fix memory optim cause by reset lod op.

    test=release/1.5

fix mask rcnn
add interface for setting optim_cache_dir(eg: when in trt int8 mode, and load model from memory, there should be a interface for setting the trt calibration table data dir)

test=release/1.5

* fix: when use the load model from memory mode, the RAM occupy is high

test=release/1.5

test=develop

size_t is an unsigned integer, with a conversion rank
 larger than int, therefore in the following expression
 the int value was promoted to size_t, making it a
 subtraction of unsigned values. The result of such
 a subtraction is also an unsigned value.