Enable references to global constants in parametric defaults.

This basically requires more careful control of the order of conversion from InferenceTable to TypeInfo, because ConstexprEvaluator presumes all prerequisites are proactively loaded.

This also changes inference_table_test to be more of a pure unit test for the table functions, because we are now at the point where equivalent end-to-end testing is being done with less hackery in typecheck_module_v2_test. The hackery previously in inference_table_test relied on the table being the source of node order.

PiperOrigin-RevId: 709194186

Update error message to be more actionable when a comment was deleted…

Optionally record pass metrics into a proto file.

This information can be useful for figuring out what passes did what and which passes actually ran and how many times they ran. This information was previously only available in the verbose logs.

PiperOrigin-RevId: 708054013

[XLS] Make sure the IR minimizer respects state-read arguments of nex…

Automated Code Change

PiperOrigin-RevId: 707401174

Allow configuration of i/o flop on per-channel basis in IR

This adds support for input_flop_kind and output_flop_kind on channels. If present these override the codegen `--flop_inputs[_kind=...]` and `--flop_outputs[_kind=...]` flags for ports associated with those channels. These should be generated by the frontend or added by some other pass. These options have no effect on the semantics of the proc ir and are only a directive for codegen conversion.

PiperOrigin-RevId: 706887241

Update xls/ir subpackage to follow updated StatusOr style guidance at…

Merge pull request #1780 from xlsynth:cdleary/2024-12-09-c-apis-for-c…

[XLS] Avoid creating cycles when merging channel operations

It is possible for our mutual-exclusion pass to determine that operations are mergeable in such a way that, if all merges are carried out, we will end up creating a cycle. For instance, if we have mergeable classes {A, C} and {B, D}, where D depends on A and C depends on B, we would end up introducing a cyclic dependency.

To avoid this, we check before merging operations whether the result would add a cyclic dependency. If it would, we prevent the merge; if the channels are using `proven_mutually_exclusive` strictness, we produce a more useful error.

Fixes google/xls#1716

PiperOrigin-RevId: 705261047

Merge pull request #1774 from xlsynth:cdleary/2024-12-06-fuzz-xn

PiperOrigin-RevId: 704973407