Summary:
A number of places were extracting dependencies from manifests, but only one was adding in the implicit dependencies for build tools.

Extract the logic to one place and use so that a change in a tool like cmake will now correctly affect all tools using cmake, as it will be taken into account as a dependency hash when the manifest's hash is computed.

Tests for this change revealed that install_dirs needed to be populated in reverse order from the manifest topo-sort, so have also addressed that

Reviewed By: wittgenst

Differential Revision: D32730717

fbshipit-source-id: 1b2a25e460de6085d274c99acfd391b3bd259264