fix(agc): allocate oversized descriptor sets from a dedicated pool

[Celegans12]

What

DescriptorCache::Allocate returns no set when a set needs more descriptors of one type than a chain pool holds (4,096 storage buffers, 1,024 sampled or storage images, 512 samplers). A build's own set falls back to a pool of its own, but PrepareDrawBindings has none and throws draw snapshot descriptor allocation failed, so the draw is skipped.

• Such a set now gets a pool sized to it (maxSets 1, no FREE_DESCRIPTOR_SET_BIT), which Free destroys; the cache destroys any left at teardown. A build's set and each of its draw snapshots get their own.
• Each type's count is first checked against the device's per-set limit for it (maxDescriptorSetSampledImages and so on); other types throw. Per-stage limits stay checked where ShaderResources plans bindings.
• The [descriptors] profile line counts the dedicated pools.
• PPSA26344 v1.008: with feat(agc): implement image and sampler tables indexed at runtime offsets #757's image tables, the DRAW_INDIRECT with color target 0x5063bf0000 (over 16,000 sampled images) is skipped on every attempt, 36 times in 2,700 s.
• Overlaps: feat(recompiler): bindless image tables up to the device's sampled-image limit #1184 also serves oversized sets in DescriptorCache::Allocate, by growing a new chain pool's count to the next power of two, and conflicts in that loop. perf(agc): pipeline queue-0 draw commits behind the packet worker #1201 and perf(agc): pipelined draws on by default #1202 recycle draw-snapshot sets and fall back to vkFreeDescriptorSets, which a dedicated pool (no FREE_DESCRIPTOR_SET_BIT) must not take; they conflict next to dedicated, and fix(agc): record depth surface lookups and fast-prove held surfaces #1199 next to this test's call. fix(agc): keep RADV's descriptor pool overrun inside the pool's pages #1065 pads the chain pools against a RADV overrun in pools with FREE_DESCRIPTOR_SET_BIT; the dedicated pools are linear, which RADV bounds. feat(agc): implement image and sampler tables indexed at runtime offsets #757-feat(agc): implement deferred faults for reads through null SRT pointers #759 and feat(agc): implement image_load through image tables #920 add a DescriptorCache::Layout parameter and merge cleanly.

Tested

• Windows 11, MinGW-w64 GCC 15.2.0, based on main c5e1018: configure -DBUILD_TESTING=ON, full build, --target libs, ctest:
• 396/396 tests pass (ctest --output-on-failure)
• Same build on lavapipe (Mesa 26.2.4 llvmpipe, 8-wide subgroups, VK_DRIVER_FILES): 395/395 pass; agc_driver_flat_store is left out there because it takes several minutes on Windows llvmpipe
• New agc_driver_oversized_descriptor_sets (GPU): two 4,097-buffer sets get a pool each and a dispatch reads through one. Fails on main.
• agc_driver_graphics: dedicated pool sizes, flags and Free, chain-sized sets, limit and type checks. Fails on main.
• PPSA26344 v1.008: a 2,700 s run with this change has no draw snapshot descriptor allocation failed skips (409 without it); it made 628 dedicated pools, and the DRAW_INDIRECT into 0x5063bf0000 bound 16,386 sampled images and was recorded.
• Not tested: Linux (CI), console behaviour.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed in TechnicalDebt
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• AI-assisted: yes

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
#1315	core/libs/prx/libSceAgcDriver/tests/Graphics.cpp L1123, L1220, L2473-2474
#1318	core/libs/prx/libSceAgcDriver/tests/Graphics.cpp L1123, L1220, L2473-2474
#1364	core/libs/prx/libSceAgcDriver/Graphics/src/ShaderResources.cpp L1189
#1366	core/libs/prx/libSceAgcDriver/Graphics/src/ShaderResources.cpp L1189

[adriadam10]

Checked on the merge with current main: build + ctest 434/434, agc_driver_graphics and agc_driver_oversized_descriptor_sets pass (the latter ran for real on RADV, not skipped), both fail without the change, CI green on the head, no conflicts. Dedicated pool sizing/flags/Free, the per-set limit check and the unsupported-type throw are pinned by the tests. Merging.

The PPSA26344 numbers are the author's and not reproduced here. #1184, #1201 and #1202 touch the same Allocate code and will need a rebase on top of this.