[Remarks] Reject remarks of type Unknown in the bitstream parser (#242617)
The bitstream remark parser only rejected type values above
`Type::Last`, so a record with type 0, `Type::Unknown`, parsed as a
valid remark. Writing such a remark as YAML reaches
`llvm_unreachable("Unknown remark type")` in `YAMLRemarkSerializer.cpp`,
which is how `llvm-remarkutil bitstream2yaml` crashes on a container
with a zeroed type field. The YAML parser already rejects a remark
without a type.
Reject type 0 with the existing "Unknown remark type." error. The new
test serializes a remark without a type and expects that error.
Assisted-by: Claude Code (Claude Fable 5.2)
[Mips] Report tail call support only where the backend makes tail calls (#241817)
The MIPS backend makes tail calls only with -mips-tail-calls, which is
off by default, and never in MIPS16 code, and a call marked `musttail`
that it can't make is a fatal error. `MipsTTIImpl` doesn't override
`supportsTailCalls`, though, so it reports tail calls as supported, and
CoroSplit marks the resume call of every symmetric transfer `musttail`.
Any C++20 coroutine that resumes another one by symmetric transfer, as
from an `await_suspend` that returns a `coroutine_handle`, then fails to
compile for every MIPS ABI, at every optimization level:
```
fatal error: error in backend: failed to perform tail call elimination on a call site marked musttail
```
#198943 closed #47971, an earlier report of this, by making the resume
functions use the C calling convention, but the backend refuses every
tail call without -mips-tail-calls.
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[mlir][SPIR-V] Add ComplexToSPIRV lowering for complex.pow (#242263)
Decomposes complex.pow using its polar-form decomposition into the real
and imaginary components, following the same pattern as the other
transcendental complex ops in this file
[SCCP] Only invalidate calls of a function when its return value is reset (#241671)
Fixes #241244.
When FunctionSpecializer resets the lattice of a function's return
value, SCCPInstVisitor::invalidate added every user of the function to
the invalidation list. That includes uses that only pass the function's
address, like `call @g(ptr @k)`. Nothing solves such a call again, so
its result stayed undef and IPSCCP folded it to undef.
Only direct calls of the function whose signature matches depend on its
return value, so invalidate now walks only those. The walk is separate
from the one for ordinary values.
security/tailscale: Update to 1.104.7.
- Update USES to imply dependency on go as intended by upstream
MFH: 2026Q4
(cherry picked from commit e331550286bcd1c78834bbfcd0368865a0a87cf4)
