spirv: implement SPV_KHR_maximal_reconvergence

Reviewed-by: Georg Lehmann <dadschoorse@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27277>

src/compiler/shader_info.h

@@ -347,6 +347,11 @@ typedef struct shader_info {
     */
    bool uses_printf:1;
 
+   /**
+    * VK_KHR_shader_maximal_reconvergence
+    */
+   bool maximally_reconverges:1;
+
    /**
      * Set if this shader uses legacy (DX9 or ARB assembly) math rules.
      *

src/compiler/spirv/spirv_to_nir.c

@@ -5521,6 +5521,10 @@ vtn_handle_execution_mode(struct vtn_builder *b, struct vtn_value *entry_point,
       break;
    }
 
+   case SpvExecutionModeMaximallyReconvergesKHR:
+      b->shader->info.maximally_reconverges = true;
+      break;
+
    case SpvExecutionModeLocalSizeId:
    case SpvExecutionModeLocalSizeHintId:
    case SpvExecutionModeSubgroupsPerWorkgroupId: