Embedding HT.entity into ST.entity + equality
Summary: We extend `Shape_analysis_types.entity_`such that it embeds `Hips_types.entity` and implement an equality function `val is_same_entity : Hips_types.entity -> Shape_analysis_types.entity_ -> bool`. The latter will be used to instantiate a module of type `Intra` for shape-like-dict, see
D38290182 (https://github.com/facebook/hhvm/commit/
340cc0f837a1cb42dfa042596265e0d484e9adc7).
Reviewed By: madgen
Differential Revision:
D38501584
fbshipit-source-id:
f447e6fb23a710dd39be7e0faf24b7c0139c29d9