What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind bug

/kind task
/kind feature

What does this PR do / why do we need it:
remove redundant preprocess in arithmetic operator and fix cast_fp16 bug

Which issue(s) this PR fixes:

Fixes #I29BKP:[MSLITE]remove redundant preprocess in arithmetic operator
#I2A4FV:[MS][Lite] ST probability failure in daily version < densenet-9.onnx >

Special notes for your reviewers: