Add support for source-specific flags

Summary:
This diff does two things:
1. Adds support for source-level flags and stamp out all the necessary code because it is clearer and less prone to bugs than manually specifying properties in code like ConsumeRefImpl (given the code stamping macros don't have bugs obv). Jan suggested this.
2. Adds source-level flags {Consume|MayMove|Move} to denote whether the instruction consumed/may have moved/moved the source. This is more specific than the CRc flag, which will be deleted in the next diff.

Putting a BE tag on it since it seems like so and also makes it easier to add more more types of flags in the future. I might add one that signifies whether a source got incref'd or not.

Reviewed By: jano

Differential Revision: D76465509

fbshipit-source-id: 2602e3d73db3048f51a44787b006fe33ae750e80

Author: chessvivek