types: fix wrong hash key for decimal (#19131)#19185

Merged

ti-srebot merged 3 commits intopingcap:release-3.0from ti-srebot:release-3.0-0448a5487519

Aug 14, 2020

+49-3

Commits on Aug 13, 2020

cherry pick pingcap#19131 to release-3.0

lzmhhh123
authored and
ti-srebot
committed

Commits on Aug 14, 2020

fix conflicts
lzmhhh123
committed
fix
lzmhhh123
committed