Fix IoMap variable names

Output struct

Lazy Vertex IO

Output fixes

Fix output struct definition

MSL Binding Model description

Might need tweaks/adjustments

Cleanup

Typo + Format

src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/InstGen.cs

@@ -70,6 +70,10 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Msl.Instructions
                 {
                     return $"{op} {GetSourceExpr(context, operation.GetSource(0), context.CurrentFunction.ReturnType)}";
                 }
+                else if (inst == Instruction.Return && context.Definitions.Stage == ShaderStage.Vertex)
+                {
+                    return $"{op} out";
+                }
 
                 int arity = (int)(info.Type & InstType.ArityMask);