* UnrealHeaderTool - Fixed so destructor is declared and defined for code gen classes

* UnrealTypeDefinitionInfo - Explicitly added destructor to make sure code gen is not adding.
* Niagra - Fixed bug where function was declared as non-inline virtual but implemented as inline.
* RecastNavmesh - Made sure destructor is outside #ifdef for UHT to more easily parse the header and generate proper code

#rb Tim.Smith
#preflight 630660a4c00af5e2946af6a6

[CL 21555810 by henrik karlsson in ue5-main branch]

Engine/Source/Runtime/NavigationSystem/Private/NavMesh/RecastNavMesh.cpp

@@ -259,6 +259,10 @@ void ARecastNavMesh::Serialize( FArchive& Ar )
 	}
 }
 
+ARecastNavMesh::~ARecastNavMesh()
+{
+}
+
 #else // WITH_RECAST
 
 #include "Detour/DetourNavMesh.h"