* 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.

This reverts commit f6ec28d7974785b625e395d57cb18d1f2110fe4c.

This commit was just a terrible idea. Caused segfaults, violated the
comment in lisp.h that only eval.c should access `union specbinding`,
and didn't even improve performance.

* src/bytecode.c (exec_byte_code): Store offset in the backtrace frame
for the function being executed, before calling Ffuncall.

* src/eval.c (record_in_backtrace): Don't record the offset.
(backtrace_next, backtrace_top): Move declarations to lisp.h.

* src/lisp.h (backtrace_next, backtrace_top): Declare.

* lisp/emacs-lisp/backtrace.el (backtrace--print-flags): Use format
width specifier to line up the flags and offset nicely.

* lisp/language/misc-lang.el (composition-function-table): Reorder
Arabic composition rules in descending order of lookback.

* src/composite.c (syms_of_composite): Document the order of rules
in 'composition-function-table'.

* lisp/progmodes/project.el (project--add-to-project-list-front):
Write the project list to file only when it has changed.

* lisp/progmodes/project.el (project--ensure-file-exists): Remove.
(project--read-project-list): Set 'project--list' to nil when the
project list file doesn't exist.

* lisp/language/hebrew.el (hebrew): Add CGJ U+034F to the
combining characters supported in Hebrew compositions. (Bug#41645)