src: update postmortem constant name

This commit renames V8DBG_CLASS_MAP__INSTANCE_ATTRIBUTES__INT
to V8DBG_CLASS_MAP__INSTANCE_TYPE__UINT16_T following upstream changes.

PR-URL: #17489
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>

src/v8abbr.h

@@ -114,7 +114,7 @@
 #define V8_OFF_HEAPOBJ_MAP  \
     V8_OFF_HEAP(V8DBG_CLASS_HEAPOBJECT__MAP__MAP)
 #define V8_OFF_MAP_ATTRS  \
-    V8_OFF_HEAP(V8DBG_CLASS_MAP__INSTANCE_ATTRIBUTES__INT)
+    V8_OFF_HEAP(V8DBG_CLASS_MAP__INSTANCE_TYPE__UINT16_T)
 #define V8_OFF_TWOBYTESTR_CHARS  \
     V8_OFF_HEAP(V8DBG_CLASS_SEQTWOBYTESTRING__CHARS__CHAR)