[llvm-mca] Set the operand ID for implicit register reads/writes. NFC

Also, move the definition of InstRef at the end of Instruction.h to avoid a
forward declaration.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335363 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed