[gdb] Add jh macro for printing objects inside handles

because for some reason gdb does not want to execute
  job *handle
anymore.

Bug: v8:8238
Change-Id: I9b632f5d34048b80e1f9542de963f738f1afb613
Reviewed-on: https://chromium-review.googlesource.com/c/1332230
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57449}

tools/gdbinit

@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# Print HeapObjects.
+# Print tagged object.
 define job
 call _v8_internal_Print_Object((void*)($arg0))
 end
@@ -11,7 +11,16 @@ Print a v8 JavaScript object
 Usage: job tagged_ptr
 end
 
-# Print v8::Local handle value.
+# Print content of v8::internal::Handle.
+define jh
+call _v8_internal_Print_Object(*((v8::internal::Object**)($arg0).location_))
+end
+document jh
+Print content of a v8::internal::Handle
+Usage: jh internal_handle
+end
+
+# Print content of v8::Local handle.
 define jlh
 call _v8_internal_Print_Object(*((v8::internal::Object**)($arg0).val_))
 end