Shader: Add support for max/min intrinsic

src/Nazara/Shader/SpirvWriter.cpp

@@ -283,6 +283,8 @@ namespace Nz
 						// Require GLSL.std.450
 						case ShaderAst::IntrinsicType::CrossProduct:
 						case ShaderAst::IntrinsicType::Length:
+						case ShaderAst::IntrinsicType::Max:
+						case ShaderAst::IntrinsicType::Min:
 							extInsts.emplace("GLSL.std.450");
 							break;