Refactor SpirV classes

SpirvStatementVisitor was merged with SpirvExpressionLoad
SpirvExpressionLoadAccessMember was renamed SpirvExpressionLoad

include/Nazara/Shader/SpirvAstVisitor.inl

@@ -0,0 +1,16 @@
+// Copyright (C) 2020 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Shader generator"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Shader/SpirvAstVisitor.hpp>
+#include <Nazara/Shader/Debug.hpp>
+
+namespace Nz
+{
+	inline SpirvAstVisitor::SpirvAstVisitor(SpirvWriter& writer) :
+	m_writer(writer)
+	{
+	}
+}
+
+#include <Nazara/Shader/DebugOff.hpp>