First whack at type structs for IDA.

This commit only includes instance field structs, not class
structs/vtables/static fields.

Il2CppInspector.Common/Outputs/Namespace.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Il2CppInspector.Outputs
+{
+    /// <summary>
+    /// A utility class for managing names in a common namespace.
+    /// </summary>
+    public class Namespace
+    {
+        private readonly Dictionary<string, int> renameCount = new Dictionary<string, int>();
+
+        public void ReserveName(string name) {
+            if (renameCount.ContainsKey(name)) {
+                throw new Exception($"Can't reserve {name}: already taken!");
+            }
+            renameCount[name] = 0;
+        }
+
+        public Namer<T> MakeNamer<T>(Namer<T>.KeyFunc keyFunc) {
+            return new Namer<T>(this, keyFunc);
+        }
+
+        /// <summary>
+        /// A class for managing objects of a common type within a namespace.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public class Namer<T>
+        {
+            private Namespace ns;
+            private readonly Dictionary<T, string> names = new Dictionary<T, string>();
+            public delegate string KeyFunc(T t);
+            private readonly KeyFunc keyFunc;
+
+            public Namer(Namespace ns, KeyFunc keyFunc) {
+                this.ns = ns;
+                this.keyFunc = keyFunc;
+            }
+
+            public string GetName(T t) {
+                string name;
+                if (names.TryGetValue(t, out name))
+                    return name;
+                name = keyFunc(t);
+                // This approach avoids linear scan (quadratic blowup) if there are a lot of similarly-named objects.
+                if (ns.renameCount.ContainsKey(name)) {
+                    int v = ns.renameCount[name] + 1;
+                    while (ns.renameCount.ContainsKey(name + "_" + v))
+                        v++;
+                    ns.renameCount[name] = v;
+                    name = name + "_" + v;
+                }
+                ns.renameCount[name] = 0;
+                names[t] = name;
+                return name;
+            }
+        }
+    }
+}