Shader: Rework Swizzle and add support for swizzle store in SPIRV

include/Nazara/Shader/Ast/Enums.hpp

@@ -128,14 +128,6 @@ namespace Nz
 			UInt32,  //< ui32
 		};
 
-		enum class SwizzleComponent
-		{
-			First,
-			Second,
-			Third,
-			Fourth
-		};
-
 		enum class UnaryType
 		{
 			LogicalNot, //< !v

include/Nazara/Shader/Ast/Nodes.hpp

@@ -178,7 +178,7 @@ namespace Nz::ShaderAst
 		NodeType GetType() const override;
 		void Visit(AstExpressionVisitor& visitor) override;
 
-		std::array<SwizzleComponent, 4> components;
+		std::array<UInt32, 4> components;
 		std::size_t componentCount;
 		ExpressionPtr expression;
 	};