[CodeGen] Print jump-table index operands as %jump-table.0 in both MIR and debug output

Work towards the unification of MIR and debug output by printing `%jump-table.0` instead of `<jt#0>`.

Only debug syntax is affected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320566 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed