src: remove v8abbr.h

The definitions in v8abbr.h, except for NODE_OFF_EXTSTR_DATA, were only
used for dtrace, which has been removed.

Refs: nodejs#43652
PR-URL: nodejs#44402
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

.github/label-pr-config.yml

@@ -21,7 +21,7 @@ subSystemLabels:
   /^src\/tty_/: c++, tty
   /^src\/node_url/: c++, whatwg-url
   /^src\/node_util/: c++, util
-  /^src\/(?:node_v8|v8abbr)/: c++, v8 engine
+  /^src\/node_v8/: c++, v8 engine
   /^src\/node_contextify/: c++, vm
   /^src\/.*win32.*/: c++, windows
   /^src\/node_zlib/: c++, zlib

src/node_postmortem_metadata.cc

@@ -1,10 +1,11 @@
-#include "env.h"
 #include "base_object-inl.h"
+#include "env.h"
 #include "handle_wrap.h"
-#include "util-inl.h"
-#include "req_wrap.h"
-#include "v8abbr.h"
 #include "node_context_data.h"
+#include "req_wrap.h"
+#include "util-inl.h"
+
+#define NODE_OFF_EXTSTR_DATA sizeof(void*)
 
 #define NODEDBG_SYMBOL(Name)  nodedbg_ ## Name
 

test/cctest/test_node_postmortem_metadata.cc

@@ -5,7 +5,8 @@
 #include "req_wrap-inl.h"
 #include "tracing/agent.h"
 #include "v8.h"
-#include "v8abbr.h"
+
+#define NODE_OFF_EXTSTR_DATA sizeof(void*)
 
 extern "C" {
 extern uintptr_t