Vulkan: Add: Specialization constants

Add implementation for using specialization constants.

Benefits of using this feature:
ShaderModules are reusable
Uniformly specialized for each hardware
Easy to support scalability
Optimizing "shader programs" (e.g. extending "for" statements)

Current assumptions:
It may be useful to know whether specialization constants change when a pipeline is created.
This is because the number of Pipeline generation times can be reduced.
Therefore, its value is maintained.

@@ -38,3 +39,3 @@
 }
 
-VKPipeline VKPipeline::create_compute_pipeline(
+VKPipeline* VKPipeline::create_compute_pipeline(

@@ -1021,1 +1036,3 @@
-           << "u)\n";
+      case Type::FLOAT: {
+        /* Use uint representation to allow exact same bit pattern even if NaN. */
+        float f = *reinterpret_cast<float *>(const_cast<uint32_t *>(&sc.default_value.u));

@@ -1407,0 +1429,4 @@
+    VkSpecializationInfo null = {};
+    return null;
+  }
+  static Vector<VkSpecializationMapEntry> entries;

@@ -1407,0 +1443,4 @@
+          /* const void *pData */ constants.values.data()};
+};
+
+const VkSpecializationInfo VKShader::specialzation_ensure()

@@ -33,2 +33,2 @@
-  VKPipeline pipeline_;
-
+  std::unique_ptr<VKPipeline> pipeline_;
+  bool vk_specialtization_dirty_ = false;

@@ -464,12 +464,10 @@ void GPU_shader_bind(GPUShader *gpu_shader)
     shader->bind();
     GPU_matrix_bind(gpu_shader);
     Shader::set_srgb_uniform(gpu_shader);
-    shader->constants.is_dirty = false;

@@ -197,1 +195,3 @@
-  pipeline.update_push_constants(*this);
+  Vector<VkSpecializationMapEntry> specialization_map_entries;
+  shader->specialization_ensure(specialization_map_entries);
+  auto &pipeline = shader->pipeline_get();

@@ -72,3 +82,2 @@
 
-VKPipeline VKPipeline::create_graphics_pipeline(
-    const VKPushConstants::Layout &push_constants_layout)
+void VKPipeline::create_graphics_pipeline(std::unique_ptr<VKPipeline> &pipeline,

@@ -602,0 +603,4 @@
+{
+  VKShaderInterface *vk_interface = new VKShaderInterface();
+  vk_interface->init(info);
+  if (interface) {

@@ -686,4 +694,4 @@
   }
 
   if (result) {
     interface = vk_interface;

@@ -1001,1 +1008,3 @@
-  interface.init(info);
+  BLI_assert(interface);
+
+  VKShaderInterface &vk_interface = *(reinterpret_cast<VKShaderInterface *>(interface));