Don't call Ffuncall directly from exec_byte_code

Don't call Ffuncall directly from exec_byte_code

* src/bytecode.c (exec_byte_code): Do a good chunk of Ffuncall's
work in the Bcall ops, so Ffuncall no longer needs to be called. As
it stands, it's an ugly clone of the contents of Ffuncall (and
some of funcall_lambda). Work in progress.

* src/eval.c (record_in_backtrace_with_offset): New function. Like
record_in_backtrace but accepts the bytecode offset and stores it
in the pertinent backtrace frame.
(record_in_backtrace): Don't record the offset.
(funcall_lambda): Remove unnecessary SYMBOLP check.

* src/lisp.h (funcall_lambda, do_debug_on_call)
(record_in_backtrace_with_offset , backtrace_debug_on_exit):
Declare.