Add status_matchers.h include to buffer_mapping_test.
Add status_matchers.h include to buffer_mapping_test.

Fixes #66

PiperOrigin-RevId: 274933258

google/iree,iree-org/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree,google/iree