C++: Separate compiler option from CppDeclarationGenerator

Il2CppInspector.Common/Cpp/CppCompiler.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Il2CppInspector.Cpp
+{
+    public static class CppCompiler
+    {
+        public enum Type
+        {
+            BinaryFormat,  // Inheritance structs use C syntax, and will automatically choose MSVC or GCC based on inferred compiler.
+            MSVC,          // Inheritance structs are laid out assuming the MSVC compiler, which recursively includes base classes
+            GCC,           // Inheritance structs are laid out assuming the GCC compiler, which packs members from all bases + current class together
+        }
+
+        public static Type GuessFromImage(IFileFormatReader image) => (image is PEReader? Type.MSVC : Type.GCC);
+    }
+}