[CodeGen] Don't print "pred:" and "opt:" in -debug output

In -debug output we print "pred:" whenever a MachineOperand is a
predicate operand in the instruction descriptor, and "opt:" whenever a
MachineOperand is an optional def in the instruction descriptor.

Differential Revision: https://reviews.llvm.org/D41870

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322096 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed