[python-bindings] Fixed 3 test failures caused by typos.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190465 91177308-0d34-0410-b5e6-96231b3b80d8
Rename variables for consistency.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190466 91177308-0d34-0410-b5e6-96231b3b80d8
[python-bindings] Added test for reading a module from bitcode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190467 91177308-0d34-0410-b5e6-96231b3b80d8
[python-bindings] Export OpCode from core.py.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190468 91177308-0d34-0410-b5e6-96231b3b80d8