shader: emit float min/max as host instructions on AMD GPUs (#1761)

* shader: emit float min/max as host instructions on AMD GPUs

V_MIN_F32, V_MAX_F32, V_MIN3_F32 and V_MAX3_F32 were emulated with a
classify-and-select sequence of about a dozen instructions each, to give
the guest's NaN and signed-zero results on any host. AMD GPUs execute
GLSL.std.450 NMin/NMax with those same rules, so emit them directly when
the device is AMD and supports VK_KHR_shader_float_controls2. Each
instruction is decorated FPFastMathMode None, since
SignedZeroInfNanPreserve does not cover extended instructions. MED3 keeps
its exact emulation. KYTY_EMULATED_FLOAT_MIN_MAX=1 keeps the emulation.

In SAROS the two heaviest compute shaders get 37% and 59% faster on an
RX 9070 XT (RADV), about 4 ms of GPU time per frame.

Adds VectorMinMaxF32RuntimeEdges (runtime operands, so nothing is folded)
and a --float-min-max-only mode that runs it and
VectorMinMaxF32NanAndSignedZeroEdges with the emulation and, where
supported, with host instructions.

Developed with AI assistance (Claude Code).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* shader: gate host float min/max on RADV and check the emitted instructions

* shader: drop float controls 2 from host float min/max

* shader: drop the float min/max env override and atomic flag

* shader: pass host capabilities to the SPIR-V emitter as a profile built once per device

* shader: enable host float min/max on AMD GPUs

---------

Co-authored-by: arda <ardaeska@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: nmzik <Nmzik@mail.ru>

tests/shaderCfgTests.cpp

@@ -16350,8 +16350,8 @@ void CheckSpirvBlockSourceMapping(TestCompileResult &result) {
   Check(SpirvInstructionOpcodeCount(result.spirv, spv::OpString) == 0 &&
             SpirvInstructionOpcodeCount(result.spirv, spv::OpLine) == 0,
         "default emission unexpectedly contains source mapping");
-  const auto mapped = Spirv::EmitProgram(result.program, options.input_info, 0,
-                                         false, true);
+  const auto mapped =
+      Spirv::EmitProgram(result.program, options.input_info, 0, {}, true);
   CheckSpirvBinaryValidates(mapped);
   uint32_t source = 0;
   uint32_t label = 0;