tu: Rename per_samp to sample_shading to match ir3.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36429>

src/freedreno/vulkan/tu_cmd_buffer.cc

@@ -6361,7 +6361,7 @@ tu6_build_depth_plane_z_mode(struct tu_cmd_buffer *cmd, struct tu_cs *cs)
       zmode = A6XX_EARLY_Z_LATE_Z;
 
    if (zmode == A6XX_EARLY_Z_LATE_Z &&
-       (cmd->state.stencil_written_on_depth_fail || fs->fs.per_samp ||
+       (cmd->state.stencil_written_on_depth_fail || fs->fs.sample_shading ||
         !vk_format_has_depth(depth_format) || !ds_test_enable)) {
       zmode = A6XX_LATE_Z;
    }
@@ -6454,7 +6454,7 @@ tu_emit_fdm_params(struct tu_cmd_buffer *cmd,
                    unsigned num_units)
 {
    STATIC_ASSERT(IR3_DP_FS(frag_invocation_count) == IR3_DP_FS_DYNAMIC);
-   tu_cs_emit(cs, fs->fs.per_samp ?
+   tu_cs_emit(cs, fs->fs.sample_shading ?
               cmd->vk.dynamic_graphics_state.ms.rasterization_samples : 1);
    tu_cs_emit(cs, 0);
    tu_cs_emit(cs, 0);

src/freedreno/vulkan/tu_shader.cc

@@ -2855,7 +2855,7 @@ tu_shader_create(struct tu_device *dev,
    }
    case MESA_SHADER_FRAGMENT: {
       const struct ir3_shader_variant *fs = shader->variant;
-      shader->fs.per_samp = fs->sample_shading || ir3_key->sample_shading;
+      shader->fs.sample_shading = fs->sample_shading || ir3_key->sample_shading;
       shader->fs.has_fdm = key->fragment_density_map;
       if (fs->has_kill)
          shader->fs.lrz.status |= TU_LRZ_FORCE_DISABLE_WRITE;

src/freedreno/vulkan/tu_shader.h

@@ -95,7 +95,11 @@ struct tu_shader
       } tes;
 
       struct {
-         bool per_samp;
+         /* Set if the FS should be run at sample rate instead of pixel rate (by
+          * sample-rate variable usage, or
+          * VkPipelineMultisampleStateCreateInfo->sampleShadingEnable.
+          */
+         bool sample_shading;
          bool has_fdm;
 
          uint16_t dynamic_input_attachments_used;
@@ -116,7 +120,7 @@ struct tu_shader_key {
    unsigned multiview_mask;
    uint16_t read_only_input_attachments;
    uint8_t max_fdm_layers;
-   bool force_sample_interp;
+   bool force_sample_interp; /* Set when VkPipelineMultisampleStateCreateInfo->sampleShadingEnable */
    bool fragment_density_map;
    bool fdm_per_layer;
    bool dynamic_renderpass;