@rdmarsh2 has been working on various queries and libraries on top of the IR, and has pointed out that having to always refer to an operand of an instruction by the pair of (instruction, operandTag) makes using the IR a bit clunky. This PR adds a new `Operand` IPA type that represents an operand of an instruction. `OperandTag` still exists, but is now an internal type used only in the IR implementation.
Moved IR flavors into "implementation", with internal files under "implementation/internal". Made `IRBlockConstruction` just a nested module of `IRConstruction`/`SSAConstruction`, so it gets picked up from the `Construction` parameter of the `IR` module, rather than being picked up just from being in the same directory as `IRBlock`.
There are no real code changes here, other than to fix up `import`s. All tests still hae the same output, as expected.
A future commit will hide the IR flavors other than the one we want queries to use directly.
This file is used by the `sync-identical-files.py` pull-request check in
our internal repo, which can hopefully soon start running on this repo
as well. This initial commit moves over all the file group definitions
whose files are entirely within this repository.
This change is not synchronized with the internal repo, so the file
groups will appear in both repositories until they sync up. That should
not cause any problems.
