feat(agc-driver): execute boolean SET_PREDICATION - #742

What

The executor rejected SET_PREDICATION ("GPU query predication is not implemented") and every packet with the predicate header bit except the tag markers. PPSA14632 (LEGO Horizon Adventures) predicates an INDIRECT_BUFFER call on a 64-bit value its GPU work writes: sceAgcDcbSetPredication(condition 1, operation 3, wait 1, address), then sceAgcSetPacketPredication(call, 1) (#582), then operation 0.

• SET_PREDICATION keeps the queue's predication, decoded as in Mesa's sid.h: operation 3 reads 64 bits, 4 reads 32 bits, bit 8 runs predicated packets when the value is non-zero (clear: when it is zero), bit 12 is a hint and is ignored, operation 0 clears it. Z-pass and primitive-count predication still throw, as do the continue bit and an address with its low 4 bits set (sceAgcDcbSetPredication writes it 16-byte aligned).
• Predicated packets. The predicate bit is accepted on every packet but SET_PREDICATION and COND_EXEC. While predication is active, the executor records the queued labels and reads the value before the packet, as COND_EXEC (feat(agc): implement COND_EXEC #673) does, and skips the packet when the predicate fails, before any of its side effects. With predication cleared the packet runs, as on the command processor.
• Predicated INDIRECT_BUFFER. Calls are inlined when a submission is copied, so a predicated call keeps its header in front of the inlined commands and records their end in conditionalEnds, like a COND_EXEC range. The whole block runs or is skipped on one evaluation. A predicated chain, a REWIND or flip or rendering wait inside a predicated call throw.

The assumptions are recorded in TechnicalDebt.

Tested

• Arch Linux, GCC 16.2, Release, based on 823e01e3. agc_driver_pm4 now covers:
  • every operation and both polarities, 32- against 64-bit reads, and each rejection;
  • the predicate bit on draws and events;
  • an end-to-end submission in which a predicated WRITE_DATA and a predicated call to a nested buffer are skipped for a false predicate and run for a true one, plus the rejected predicated chain. With the copy change reverted it fails ("command buffer with a false predicate was executed").
• Five existing checks used bit 0 as the example of an unsupported header flag (agc_driver_pm4, agc_driver). They now use a flag that is still unsupported for that packet.
• Full ctest: 308/308 apart from the three wave64 pixel tests that fail on main on this GPU (RX 9070 XT, RADV).
• PPSA14632 with feat(agc): implement packet and range predication and the predication sizes #582 and the title's other open fixes: the predicated submission runs, the Vulkan device is created and the title stops later at sceAgcDcbSetCxRegistersIndirect with a null address.
• Windows not built or tested.

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 (complements feat(agc): implement packet and range predication and the predication sizes #582, which sets the predicate bit from libSceAgc)
• AI-assisted: yes

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