Remove from_text from full_fidelity_ast
Summary:
When the parser is rustified, the legacy ast should hopefully disappear along with it. So I am trying to front run some of that work by removing existing references to the legacy by containing them to an implementation detail in lowering in full_fidelity_ast and removing calls that expose the legacy ast in the mli file. That way, when the lowerer is ported and goes straight to the aast, it can just be a drop in for everything.
This diff removes `from_text` from the interface and attempts to replace it with a `from_text_to_empty_tast` function that provides the functionality for `hh_single_compile` to take a file and get an untyped tast.
Some tests were modified:
Tests previously printing out the legacy ast now print out the equivalent aast.
Tests that previously had codepaths with trait resolution (`insteadof`) (`use as`) were deleted as those are php features that Hack does not support.
Reviewed By: shiqicao
Differential Revision:
D17695710
fbshipit-source-id:
ae7ad41851b88e04e3b4039b5fb1f8fe6d94ad72