Fix crash when using attributes cache after hot-reload in editor

Source/Engine/Scripting/ManagedCLR/MAssembly.h

@@ -14,6 +14,7 @@
 /// </summary>
 class FLAXENGINE_API MAssembly
 {
+    friend MCore;
     friend MDomain;
     friend Scripting;
 

Source/Engine/Scripting/ManagedCLR/MEvent.h

@@ -10,6 +10,7 @@
 class FLAXENGINE_API MEvent
 {
     friend MClass;
+    friend MCore;
 
 protected:
 #if USE_MONO

Source/Engine/Scripting/ManagedCLR/MField.h

@@ -11,6 +11,7 @@
 class FLAXENGINE_API MField
 {
     friend MClass;
+    friend MCore;
 
 protected:
 #if USE_MONO

Source/Engine/Scripting/ManagedCLR/MMethod.h

@@ -16,6 +16,7 @@ class FLAXENGINE_API MMethod
     friend MClass;
     friend MProperty;
     friend MEvent;
+    friend MCore;
 
 protected:
 #if USE_MONO

Source/Engine/Scripting/ManagedCLR/MProperty.h

@@ -12,6 +12,7 @@
 class FLAXENGINE_API MProperty
 {
     friend MClass;
+    friend MCore;
 
 protected:
 #if USE_MONO

Source/Engine/Scripting/Runtime/DotNet.cpp

@@ -336,7 +336,46 @@ void MCore::ReloadScriptingAssemblyLoadContext()
 {
     // Clear any cached class attributes (see https://github.com/FlaxEngine/FlaxEngine/issues/1108)
     for (auto e : CachedClassHandles)
+    {
+        e.Value->_hasCachedAttributes = false;
         e.Value->_attributes.Clear();
+    }
+    for (auto e : CachedAssemblyHandles)
+    {
+        MAssembly* a = e.Value;
+        if (!a->IsLoaded() || !a->_hasCachedClasses)
+            continue;
+        for (auto q : a->GetClasses())
+        {
+            MClass* c = q.Value;
+            c->_hasCachedAttributes = false;
+            c->_attributes.Clear();
+            if (c->_hasCachedMethods)
+            {
+                for (MMethod* m : c->GetMethods())
+                {
+                    m->_hasCachedAttributes = false;
+                    m->_attributes.Clear();
+                }
+            }
+            if (c->_hasCachedFields)
+            {
+                for (MField* f : c->GetFields())
+                {
+                    f->_hasCachedAttributes = false;
+                    f->_attributes.Clear();
+                }
+            }
+            if (c->_hasCachedProperties)
+            {
+                for (MProperty* p : c->GetProperties())
+                {
+                    p->_hasCachedAttributes = false;
+                    p->_attributes.Clear();
+                }
+            }
+        }
+    }
 
     static void* ReloadScriptingAssemblyLoadContextPtr = GetStaticMethodPointer(TEXT("ReloadScriptingAssemblyLoadContext"));
     CallStaticMethod<void>(ReloadScriptingAssemblyLoadContextPtr);