Bump LLVM to 26ff16663777fc995e8c6b46fa2433610dab4f64.

[mikeurbach]

This appears to be a clean bump.

[mikeurbach]

I know we are long overdue for an LLVM bump... @uenoku I saw the linked PR, which was then reverted. Do you think the CI fails are related to circt-lsp-server?

[uenoku]

I debugged a bit more but it turned out lsp unittest was not root cause (https://github.com/llvm/circt/actions/runs/20674012325 is a CI run that disabled lsp unittests entirely and still failed)..

[uenoku]

https://github.com/llvm/circt/actions/runs/20732951411/job/59524531509

Ok it seems like Dialect/FIRRTL/grand-central.mlir is hanging.

TIMEOUT: CIRCT :: Dialect/FIRRTL/grand-central.mlir (1030 of 1030)
******************** TEST 'CIRCT :: Dialect/FIRRTL/grand-central.mlir' FAILED ********************
Exit Code: -9
Timeout: Reached timeout of 60 seconds

Command Output (stderr):
--
circt-opt --verify-roundtrip -pass-pipeline='builtin.module(firrtl.circuit(firrtl-grand-central,symbol-dce))' -split-input-file /__w/circt/circt/test/Dialect/FIRRTL/grand-central.mlir | /__w/circt/circt/llvm/install/bin/FileCheck /__w/circt/circt/test/Dialect/FIRRTL/grand-central.mlir # RUN: at line 1
+ /__w/circt/circt/llvm/install/bin/FileCheck /__w/circt/circt/test/Dialect/FIRRTL/grand-central.mlir
+ circt-opt --verify-roundtrip '-pass-pipeline=builtin.module(firrtl.circuit(firrtl-grand-central,symbol-dce))' -split-input-file /__w/circt/circt/test/Dialect/FIRRTL/grand-central.mlir

[uenoku]

It should be good to merge now.

[jpienaar]

OK if merged? (I was going to start one and then noticed this one so thought I'd ask first)

[seldridge]

I think the right thing to do is re-bump with a commit that includes llvm/llvm-project#174874 and back out the change to disable round tripping.

[jpienaar]

Made #9443 .

[seldridge]

Superseded by github.com//pull/9443.

[mikeurbach]

Thanks @jpienaar !