[gdb] Remove $job helper

It doesn't seem to work properly, use _v8_internal_Get_Object until
we can think of a better workaround.

Bug: v8:8994
Change-Id: I47496d442f5b62e6cb78edcdf35fe1ac1aad2084
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1529005Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60348}

tools/gdbinit

@@ -163,17 +163,3 @@ def dcheck_stop_handler(event):
 
 gdb.events.stop.connect(dcheck_stop_handler)
 end
-
-# Install a $job function which returns an Object given a tagged pointer.
-# Use with print or call, casting as needed, e.g.
-#
-#   gdb$ p (v8::internal::SharedFunctionInfo)$job(0x31412531)
-python
-class Job(gdb.Function):
-  def __init__(self):
-    super(Job,self).__init__("job")
-  def invoke(self, address):
-    # TODO(leszeks): Detect the type of the object and cast it.
-    return gdb.parse_and_eval("_v8_internal_Get_Object")(address)
-Job()
-end