Add tests for llvm-bcanalyzer stream types

Summary:
Add tests for the improved stream type detection added to
`llvm-bcanalyzer` in https://reviews.llvm.org/D41979.

Test Plan: `check-clang`

Reviewers: pcc, aprantl, mehdi_amini, george.karpenkov

Reviewed By: aprantl

Subscribers: cfe-commits, a.sidorin

Differential Revision: https://reviews.llvm.org/D41980