Merge pull request #2811 from hzeller:feature-20250808-inline-constexpr

PiperOrigin-RevId: 792780388

Migrate away from ArrayRef(std::nullopt_t)

The upstream LLVM has deprecated ArrayRef(std::nullopt_t).  This CL migrates away from that.

PiperOrigin-RevId: 792491328

Ensure pass_profile works correctly even if multiple threads are runn…

Factor out SweepPipelineStagesFixture to passes_ng_text_fixtures.h.

PiperOrigin-RevId: 791354381

Merge pull request #2769 from hzeller:feature-20250802-use-stdlib-rea…

Rewrite SLessThan using ITE in abstract eval.

PiperOrigin-RevId: 789957912

Include evaluation results in TIv2 traces, and stop truncating the st…

Switch some errors away from InternalError().

We generally don't care too much about which abseil error code we use, but these really seem more like invalid arguments than internal errors.

The motivation is to fuzz codegen for correctly-returned errors. We want InternalErrors to be "bad" fuzz findings and InvalidArgumentErrors (among others) will be "good" fuzz findings.

PiperOrigin-RevId: 788681051

xls/examples/matmul_4x4: load weights from channel

- add weight state to PE node
- add one-of weights load on first activation
- send weights from test
- improve comments

PiperOrigin-RevId: 788272142

Add FuzzTestPrintSourceCode implementations for a few types

In a near future version of gfuzztest this function allows one to override source-code printing for these types.

This uses https://github.com/google/fuzztest/pull/1780.

PiperOrigin-RevId: 787288665