Added temp arena and use it in hot reload

Juliet/include/Core/Memory/MemoryArena.h

@@ -51,6 +51,12 @@ namespace Juliet
     };
     static_assert(sizeof(Arena) <= k_ArenaHeaderSize);
 
+    struct TempArena
+    {
+        Arena*  Arena;
+        index_t Position;
+    };
+
     struct ArenaParams
     {
         uint64 ReserveSize = g_Arena_Default_Reserve_Size;
@@ -97,4 +103,7 @@ namespace Juliet
         return static_cast<Type*>(ArenaPush(arena, sizeof(Type) * count, Max(8ull, AlignOf(Type)),
                                             true JULIET_DEBUG_ONLY(, typeid(Type).name())));
     }
+
+    TempArena ArenaTempBegin(NonNullPtr<Arena> arena);
+    void      ArenaTempEnd(TempArena temp);
 } // namespace Juliet

Juliet/src/Core/HotReload/Win32/Win32HotReload.cpp

@@ -56,8 +56,8 @@ namespace Juliet
                 basePathLength + StringLength(code.TransientDLLName) + /* _ */ 1 + kTempDLLBufferSizeForID + 1 /* \0 */;
 
             // Allocate from Scratch Arena (transient)
-            index_t pos         = ArenaPos(code.Arena);
-            auto    tempDllPath = ArenaPushArray<char>(code.Arena, tempDllMaxBufferSize);
+            TempArena temp        = ArenaTempBegin(code.Arena);
+            auto      tempDllPath = ArenaPushArray<char>(temp.Arena, tempDllMaxBufferSize);
 
             for (uint32 attempt = 0; attempt < kMaxAttempts; ++attempt)
             {
@@ -97,7 +97,7 @@ namespace Juliet
                     break;
                 }
             }
-            ArenaPopTo(code.Arena, pos);
+            ArenaTempEnd(temp);
 
             code.Dll = LoadDynamicLibrary(tempDllPath);
             if (code.Dll)

Juliet/src/Core/Memory/MemoryArena.cpp

@@ -327,4 +327,15 @@ namespace Juliet
         size_t position = current->BasePosition + current->Position;
         return position;
     }
+
+    TempArena ArenaTempBegin(NonNullPtr<Arena> arena)
+    {
+        index_t position = ArenaPos(arena);
+        return { arena.Get(), position };
+    }
+
+    void ArenaTempEnd(TempArena temp)
+    {
+        ArenaPopTo(temp.Arena, temp.Position);
+    }
 } // namespace Juliet