Put #if 0 blocks around three sections of code that are intentionally
unreachable so we don't get warnings about them.

Completely initialize a structure instead of leaving some of its fields
potentially indeterminate (although in reality they would all be set 
before use -- but the compiler warning doesn't know that).

clang warning.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@220017 91177308-0d34-0410-b5e6-96231b3b80d8