[Vulkan] Truncate depth to float24 in EDRAM range ownership transfers and resolves by default

Doesn't ruin the "greater or equal" depth test in subsequent rendering passes if precision is lost, unlike rounding to the nearest

src/xenia/gpu/spirv_shader_translator.h

@@ -208,10 +208,11 @@ class SpirvShaderTranslator : public ShaderTranslator {
                               spv::Id ext_inst_glsl_std_450);
   // Converts the depth value externally clamped to the representable [0, 2)
   // range to 20e4 floating point, with zeros in bits 24:31, rounding to the
-  // nearest even. If remap_from_0_to_0_5 is true, it's assumed that 0...1 is
-  // pre-remapped to 0...0.5 in the input.
+  // nearest even or towards zero. If remap_from_0_to_0_5 is true, it's assumed
+  // that 0...1 is pre-remapped to 0...0.5 in the input.
   static spv::Id PreClampedDepthTo20e4(spv::Builder& builder,
                                        spv::Id f32_scalar,
+                                       bool round_to_nearest_even,
                                        bool remap_from_0_to_0_5,
                                        spv::Id ext_inst_glsl_std_450);
   // Converts the 20e4 number in bits [f24_shift, f24_shift + 10) to a 32-bit