vulkan backend ops: implemented GATED_LINEAR_ATTN

[PranavUttarkar]

Overview

Added vulkan support for GGML_OP_GATED_LINEAR_ATTN

This backend op used to not be supported on vulkan and fell back to cpu. Now the kernel follows the existing wkv6.comp pattern w/ a GLA-specific update-before-read ordering and an output "scale" push constant.

supports_op is limited to F32 and head_size == 64 (shader hardcodes BLOCK_SIZE 64, same as WKV6).

Part of #14909

Additional information

Modeled on the vulkan WKV6 path. Checked against the CPU reference in ggml_compute_forward_gla_f32

Test results (AMD Radeon 780M, Windows)

test-backend-ops.exe test -b Vulkan0 -o GATED_LINEAR_ATTN 4/4 tests passed

adjacent recurrence ops after rebase:

• RWKV_WKV6: 4/4
• RWKV_WKV7: 4/4
• GATED_DELTA_NET: 36/36
  Full Vulkan0 suite: 14400/14443. Remaining failures are preexisting DIV(type=f16, ...)`NMSE misses on this device/driver. reproduced on clean master with this change stashed and they remain.

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure:
  YES: AI was used in the beginning to understand the codebase and for easier search and navigation to different similar points. Code was all handwritten and then AI was used to review correctness and any gaps/oversights.

[ggml-gh-bot]

Hi @PranavUttarkar, thanks for your contribution!

Per our contribution guidelines, the automated PR checker found the following issue(s) that need your attention:

• PR Template not respected: Please respect the template when creating a new pull request. Make sure to fill out all required sections.

• Large PR: Large changes require prior discussion (e.g. an issue or RFC) and maintainers may not be able to review this PR as-is. Consider splitting it into smaller, focused PRs.

---

Please note that maintainers reserve the right to make final decisions on PRs. If you believe there is a mistake, please comment below.

[PranavUttarkar]

Hi @PranavUttarkar, thanks for your contribution!

Per our contribution guidelines, the automated PR checker found the following issue(s) that need your attention:

• PR Template not respected: Please respect the template when creating a new pull request. Make sure to fill out all required sections.
• Large PR: Large changes require prior discussion (e.g. an issue or RFC) and maintainers may not be able to review this PR as-is. Consider splitting it into smaller, focused PRs.

Please note that maintainers reserve the right to make final decisions on PRs. If you believe there is a mistake, please comment below.

Not a Large PR. maybe the bot thinks so due to the vulkan.csv file updated with this:
test-backend-ops support --output csv -b Vulkan0 > docs/ops/Vulkan.csv

PR follows the template