Add a getSizeInBits() accessor to MachineMemOperand. NFC.

Cleans up a bunch of places where we do getSize() * 8.

Differential Revision: https://reviews.llvm.org/D60799

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358617 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed