CI: add hip quality check

[IMbackK]

Add "hip-check" ci workflow, this workflow is intended to solve the following problems for us:

1. The hip backend has had repeated problems with people adding #pragma unroll loops that cant be unrolled see ssm-conv, softmax and CUDA: use shared mem for ssm_conv #20128 (comment)
   • this workflow builds the hip backend with Werror to make it obvious when these occure
   • i did not make the hip builds Werror generally as we can not guarentee that there will be no warnings when built against every rocm version we support
2. Currently we want to support rocm >=6.1 so build for 6.1 in the build workflow to check that no functions from newer rocm sneak in, however we build the release against the latest version of rocm, this causes the issue that we dont notice if a pr dosent build against the latest version until the release fails
   • This workflow builds against the same version of rocm as the release to check for this
3. GCN/CDNA have a rather small 64 KiB vector register file and are wave 64, which means that only 256 registers are available. Quite often kernels get added that include significant register spill.
   • This pr adds a small script that is used in the workflow to check for kernels that spill significant registers
   • The script ignores kernels with significant spills currently in the code base (altho several of these should be investigated at some point)

The idea of this workflow that its failure NOT necessarily block a pr, but that its should prompt investigation / possible adding to the workflows witelist.

[IMbackK]

theres a run here https://github.com/IMbackK/llama.cpp/actions/runs/22975551980/job/66703103556 to show how this works (the failure in the VGPR check is on purpose for illustration)

[IMbackK]

@CISC the hip compiler will ignore #pragma clang diagnostic push when --save-temps is active. For this reason a build with -DGGML_HIP_EXPORT_METRICS=On and -Werror can not succeed as warning will be emmited here:

llama.cpp/ggml/src/ggml-cuda/softmax.cu

Line 51 in f2ab047

#pragma clang diagnostic push

among other places.

[CISC]

Better split the jobs again then.

[IMbackK]

Right

[CISC]

Check CI failures.