[llvm.py] Implement interface to enhanced disassembler

This requires a C++ change to EDDisassembler's ctor to function properly
(the llvm::InitializeAll* functions aren't being called currently and
there is no way to call them from Python).

Code is partially tested and works well enough for initial commit. There
are probably many small bugs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152506 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed