* lisp/profiler.el: Create a more coherent calltree from partial backtraces.

* lisp/profiler.el: Create a more coherent calltree from partial backtraces.
(profiler-format): Hide the tail with `invisible' so that C-s can still
find the hidden elements.
(profiler-calltree-depth): Don't recurse so enthusiastically.
(profiler-function-equal): New hash-table-test.
(profiler-calltree-build-unified): New function.
(profiler-calltree-build): Use it.
(profiler-report-make-name-part): Indent the calltree less.
(profiler-report-mode): Add visibility specs for profiler-format.
(profiler-report-expand-entry, profiler-report-toggle-entry):
Expand the whole subtree when provided with a prefix arg.
* src/fns.c (hashfn_user_defined): Allow hash functions to return any
Lisp_Object.