Short-circuit the recursive bytecode funcall chain

Short-circuit the recursive bytecode funcall chain

Inline parts of the code for function calls to speed up the common
case of calling lexbound byte-code.  By eliminating intermediate
functions, this also reduces C stack usage a little.

* src/bytecode.c (exec_byte_code): Inline parts of Ffuncall,
funcall_lambda and fetch_and_exec_byte_code in the Bcall opcode
handler.
* src/eval.c (backtrace_debug_on_exit): Inline and move to lisp.h.
(do_debug_on_call): Make global so that it can be called from
bytecode.c.
(funcall_general): New function, essentially the meat of Ffuncall.
* src/lisp.h (backtrace_debug_on_exit): Moved here from eval.c.