Add loop rerolling code owner

I am the code owner of the loop reroller.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195271 91177308-0d34-0410-b5e6-96231b3b80d8
PPC popcnt[dw] do not have record forms

The instruction definitions incorrectly specified that popcntd and popcntw have
record forms; they do not. This mistake was causing invalid code generation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195272 91177308-0d34-0410-b5e6-96231b3b80d8