Put Shape env into its own module
Put Shape env into its own module

Summary: This is a no-op refactoring that will ease the later definition of summaries.

Reviewed By: rgrig

Differential Revision: D39935081

fbshipit-source-id: c2c07b6bf0ffff857d81580ed5ef9391d26ba580

facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer