Python compat - has_key vs. in operator

Use portable `in` operator instead of `has_key(...)` method.

Differential Revision: https://reviews.llvm.org/D56260

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350314 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed