Revert "Fix non-{arm, x86} builds."

This reverts commit 1e8ecdcaa0201064d687baa78629b1f882377a06.
Revert "More code generation for the optimizing compiler."

This reverts commit d966a52723b00156f39ab1df67ce19c87ab968d4.
Revert "Fix lint errors."

This reverts commit 5ab6c8994a777eee177a3b4e6db779b5702dfed9.
Revert "Add register support to the optimizing compiler."

This reverts commit a03e5ee78fc88edda99cb937cf1c357a8fbeb2dc.
Revert "Add codegen support to the optimizing compiler."

This reverts commit 9d31503ac740c614c09a046fe64b8a1696a71cf5.
Revert "Add conditional branches, and build dominator tree."

This reverts commit 8cccbf987640dd0e458498b6f9258235d4511db2.
Revert "Re-apply: Initial check-in of an optimizing compiler."

This reverts commit 82e1009b3049cc7df8c8ef86ed2ad9937f7db440.