v2: Fix direct this->field accesses bypassing TDEF_FIELD dispatch

get_size(), get_fqn_hash(), and get_flags() on RETypeDefinition read
fields directly via this->size / this->fqn_hash / this->type_flags,
using the compiled-in tdb84 struct layout. For DMC5 (TDB 67), these
fields are at different offsets in RETypeDefVersion67 — the direct
access read garbage, causing get_size() to return 0 and the
AutoGenerated Types section in ObjectExplorer to show nothing.

Changed all three to use TDEF_FIELD(this, field) which dispatches
to the correct version-specific struct at runtime.

Verified: DMC5 AutoGenerated Types now discovers managed objects.

Author: praydog

shared/sdk/RETypeDefinition.cpp

@@ -978,12 +978,12 @@ uint32_t RETypeDefinition::get_crc_hash() const {
 }
 
 uint32_t RETypeDefinition::get_fqn_hash() const {
-    return this->fqn_hash;
+    return TDEF_FIELD(this, fqn_hash);
 }
 
 uint32_t RETypeDefinition::get_size() const {
 #if TDB_VER > 49
-    return this->size;
+    return TDEF_FIELD(this, size);
 #else
     auto t = (regenny::via::typeinfo::TypeInfo*)get_type();
 
@@ -1261,7 +1261,7 @@ ::REObjectInfo* RETypeDefinition::get_managed_vt() const {
 
 uint32_t RETypeDefinition::get_flags() const {
 #if TDB_VER > 49
-    return this->type_flags;
+    return TDEF_FIELD(this, type_flags);
 #else
     return 0;
 #endif