Since `maybe_quit` is called on many critical paths, inline a slightly
cheaper condition (that ignores Vinhibit_quit).

* src/eval.c (maybe_quit): Rename to `probably_quit`.
* src/lisp.h (maybe_quit): New simplified inline function.

The common case is just to increment `specpdl_ptr`; do that in-line,
but move the uncommon reallocation to a separate subroutine.

* src/eval.c (grow_specpdl): Now inline, most code moved...
(grow_specpdl_allocation): ...here.

* src/eval.c (funcall_general, Ffuncall): Delegate the actual work in
Ffuncall to funcall_general which does exactly this.
This slows down some less used function call paths by a small amount
but the code duplication was just silly.

* src/bytecode.c (exec_byte_code):
Restore the previous graceful error (instead of a hard crash) when the
bytecode doesn't unwind properly, but only when building with
debugging (NDEBUG not defined, checking enabled, or BYTE_CODE_SAFE
enabled).

* src/bytecode.c (exec_byte_code): Inline aref and aset for
vectors and records, since this is important for code that makes heavy
use of arrays and/or objects.

It was implemented but never generated, originally intended for
TCO in the pre-lexbind era (which was semantically dubious anyway).
Removing it speeds up the interpreter because there is no longer any
need for the outermost `count` variable unless checking is enabled.

* lisp/emacs-lisp/bytecomp.el:
* lisp/emacs-lisp/comp.el (comp-limplify-lap-inst):
* src/bytecode.c (BYTE_CODES, exec_byte_code):
Remove definition and implementation of unbind-all, freeing up the opcode
for other purposes.

* src/bytecode.c (exec_byte_code): Turn error condition into eassert.

Since we pass no arguments to a non-lexbind bytecode function, we can
specify its arity as 0 instead of nil and save a test and branch.

* src/bytecode.c (Fbyte_code, exec_byte_code):
* src/eval.c (fetch_and_exec_byte_code, funcall_lambda):
* src/lisp.h:
Change the args_template parameter type to ptrdiff_t, since it is now
always a small integer, in exec_byte_code and
fetch_and_exec_byte_code, all callers adjusted.

Implement point_max in the same way as point_min.