[FIocker]

#1830 merged with a few non-blocking notes left from hckrman101's and Joey-Magnus's reviews; this PR is those. The main one: an offline-baked program bank didn't get the AMD noperspective workaround that live translation now has.

What it does

• The workaround baked offline too (nx2/bake_ds/bake_ds.cpp):
  • The VS+FS path now translates the fragment stage before it emits the vertex stage, as vk_shader.cpp translate_into does.
  • It sets noperspective_outputs / scaled_noperspective_inputs the same way: not with indexed fragment reads and not with transform feedback.
  • Without this, a bank baked offline kept the old interpolation, so the red dotted line and particles on AMD (Red lines #1634, [Tracking] Linux and Steam Deck: GPU hangs, crashes, low FPS and build failures #1000) came back for programs taken from it.
• RX_VK_LOWER_SKIP is in the program stamp: it's in translator_stamp's prefix list and in bake_ds.cpp's, which test_program_stamp_knobs.py keeps equal. Programs translated while it's set are kept apart in the cache, so a bisection also sees programs that were already cached. The comment says so.
• One redundant term removed: DefineInputs' loads is already info.loads.mask | info.passthrough.mask, so FragCoord's condition is just loads.AnyComponent(PositionX) || noperspective_as_smooth.
• The "(super build)" tags are gone from emit_spirv.cpp, stream.h and vk_shader.cpp.

Testing

• Builds: vk_shader.cpp, spirv_emit_context.cpp and emit_spirv.cpp compile with clang using nx2/build.py's renderer flags. bake_ds.cpp is POSIX-only; I syntax-checked it on Windows with stand-in unistd.h/dlfcn.h, so Linux CI is its real build.
• Tests: the stamp, bake and shader checks pass locally, test_program_stamp_knobs.py among them. test_bake_portability.py fails on this PC for main as well.
• Screenshots for fix(shaders): noperspective varyings interpolated right on AMD (Royal Family Tomb water); sirit names an undefined operand #1830: omgitsgela's Steam Deck run there is the before/after. If they're OK with it, their pair would go well in fix(shaders): noperspective varyings interpolated right on AMD (Royal Family Tomb water); sirit names an undefined operand #1830's description.

🤖 Generated with Claude Code

[Joey-Magnus]

I merged this into current main and ran the bake, stamp and shader checks: test_bake_ds, test_bake_portability, test_bake_skeleton, test_program_stamp_knobs, test_shader_stamp_*, test_prepared_stamps and the vk/shader/program subset of run_all. All pass. The bake_ds.cpp change matches vk_shader.cpp translate_into:1341-1348 line for line: fragment first, no indexed attribute reads, xfb_count == 0, and scaled_noperspective_inputs set from the vertex mask. Dropping the passthrough term in DefineInputs is right, since loads already ORs in passthrough. RX_VK_LOWER_SKIP is now in both prefix lists, and test_program_stamp_knobs keeps them equal. One correction to the description: no CI job builds nx2/bake_ds/bake_ds.cpp. The Linux jobs only run the source checks, and nothing in .github compiles it through nx2/bake_ds/build.sh. So it is still unbuilt after CI. I couldn't build it here either (no fmt/boost externals). Please run nx2/bake_ds/build.sh once on Linux before this merges, or ask someone who has the externals to.