Update the version of dwarf we say we're emitting to at least 3.

Deals with a dwarf2 -> dwarf3 DW_FORM_ref_addr change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179122 91177308-0d34-0410-b5e6-96231b3b80d8
Remove unused method and default values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179124 91177308-0d34-0410-b5e6-96231b3b80d8
Cleanup. No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179125 91177308-0d34-0410-b5e6-96231b3b80d8
Cleanup. No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179129 91177308-0d34-0410-b5e6-96231b3b80d8