[MC/Dwarf] Allow to specify custom parameters for linetable emission.

NFC patch for current users, but llvm-dsymutil will use the new
functionality to adapt to the input linetable.

Based on a patch by Adrian Prantl.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244318 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed