The max-lisp-eval-depth limit is sufficient to prevent unbounded stack
growth including the specbind stack; simplify matters for the user by
not having them to worry about two different limits.  This change
turns max-specpdl-size into a harmless variable with no effects,
to keep existing code happy.

* lisp/subr.el (max-specpdl-size):
Define as an ordinary (but obsolete) dynamic variable.
* admin/grammars/Makefile.in:
* doc/lispintro/emacs-lisp-intro.texi (Loops & Recursion):
* doc/lispref/control.texi (Cleanups):
* doc/lispref/edebug.texi (Checking Whether to Stop):
* doc/lispref/eval.texi (Eval):
* doc/lispref/variables.texi (Local Variables):
* doc/misc/calc.texi (Recursion Depth):
Update documentation.
* etc/NEWS: Announce.
* src/eval.c
(FletX): Use safe iteration to guard against circular bindings list.
(syms_of_eval): Remove old max-specpdl-size definition.
(init_eval_once, restore_stack_limits, call_debugger)
(signal_or_quit, grow_specpdl_allocation):
* leim/Makefile.in:
* lisp/Makefile.in:
* lisp/calc/calc-stuff.el (calc-more-recursion-depth)
(calc-less-recursion-depth):
* lisp/calc/calc.el (calc-do):
* lisp/cedet/semantic/ede-grammar.el (ede-proj-makefile-insert-rules):
* lisp/cedet/semantic/grammar.el (semantic-grammar-batch-build-one-package):
* lisp/cus-start.el (standard):
* lisp/emacs-lisp/comp.el (comp--native-compile):
* lisp/emacs-lisp/edebug.el (edebug-max-depth):
(edebug-read-and-maybe-wrap-form, edebug-default-enter):
* lisp/emacs-lisp/regexp-opt.el (regexp-opt):
* lisp/eshell/esh-mode.el (eshell-mode):
* lisp/loadup.el (max-specpdl-size):
* lisp/mh-e/mh-e.el (mh-invisible-headers):
* lisp/net/shr.el (shr-insert-document, shr-descend):
* lisp/play/hanoi.el (hanoi-internal):
* lisp/progmodes/cperl-mode.el:
* src/fileio.c (Fdo_auto_save):
Remove references to and modifications of max-specpdl-size.

Run "TZ=UTC0 admin/update-copyright".

* lisp/calc/calc-aent.el (calc-do-quick-calc)
(calc-do-calc-eval, math-build-parse-table):
* lisp/calc/calc-alg.el (math-polynomial-base):
* lisp/calc/calc-alg.el (math-is-poly-rec):
* lisp/calc/calc-arith.el (calcFunc-scf):
* lisp/calc/calc-arith.el (math-ceiling, math-round):
* lisp/calc/calc-arith.el (math-trunc-fancy, math-floor-fancy):
* lisp/calc/calc-ext.el (calc-init-extensions, calc-reset)
(calc-refresh-top, calc-z-prefix-help, calc-binary-op-fancy)
(calc-unary-op-fancy):
* lisp/calc/calc-forms.el (math-make-mod):
* lisp/calc/calc-frac.el (calcFunc-frac):
* lisp/calc/calc-funcs.el (calcFunc-euler):
* lisp/calc/calc-help.el (calc-full-help):
* lisp/calc/calc-lang.el (c, pascal, fortran, tex, latex, eqn)
(yacas, maxima, giac, math, maple):
* lisp/calc/calc-macs.el (calc-wrapper, calc-slow-wrapper):
* lisp/calc/calc-map.el (calc-get-operator, calcFunc-mapeqr)
(calcFunc-reducea, calcFunc-rreducea, calcFunc-reduced)
(calcFunc-rreduced, calcFunc-outer):
* lisp/calc/calc-misc.el (another-calc, calc-do-handle-whys):
* lisp/calc/calc-mode.el (calc-save-modes):
* lisp/calc/calc-mtx.el (math-col-matrix, math-mul-mat-vec):
* lisp/calc/calc-poly.el (math-sort-terms, math-poly-div-list)
(math-mul-list, math-sort-poly-base-list)
(math-partial-fractions):
* lisp/calc/calc-prog.el (calc-user-define-formula):
* lisp/calc/calc-rewr.el (math-rewrite, math-compile-patterns)
(math-compile-rewrites, math-parse-schedule)
(math-rwcomp-pattern):
* lisp/calc/calc-store.el (calc-var-name-map, calc-let)
(calc-permanent-variable, calc-insert-variables):
* lisp/calc/calc-stuff.el (calc-flush-caches, calcFunc-pclean)
(calcFunc-pfrac):
* lisp/calc/calc-units.el (math-build-units-table)
(math-decompose-units):
* lisp/calc/calc-vec.el (calcFunc-mrow, math-mat-col)
(calcFunc-mcol, math-mat-less-col, math-mimic-ident):
* lisp/calc/calc-yank.el (calc-edit):
* lisp/calc/calc.el
(calc-mode-var-list-restore-default-values)
(calc-mode-var-list-restore-saved-values, calc-mode, calc-quit):
* lisp/calc/calccomp.el (math-compose-expr)
(math-compose-matrix, math-vector-to-string): Don't quote lambdas with
'function'.

Includes the following pervasive changes:
- Move some defvars earlier in the file so they cover earlier let-bindings
- Change dynamically scoped `calc-FOO` or `math-FOO` function arguments
  to just FOO and then let-bind the `calc-FOO` or `math-FOO` variable
  explicitly in the body of the function.  In some cases, the
  beginning of the function was changed to refer to FOO so as to delay
  the binding to a nearby `let` when I could ensure that it did
  not make a difference.
- Add an underscore in front of unused vars or comment them out altogether.
- Replace unused `err` arg to `condition-case` with nil.

Plus the additional itemized changes below.

* lisp/calc/calc-map.el (calcFunc-reducer):
* lisp/calc/calc-arith.el (math-setup-declarations):
* lisp/calc/calc-help.el (calc-full-help, calc-help-index-entries)
(calc-full-help): Use `ignore-errors`.

* lisp/calc/calc-embed.el (calc-embedded-modes-change):
Declare `the-language` and `the-display-just` as dynamically scoped.

* lisp/calc/calc-forms.el (math-setup-year-holidays): Use `dolist`.

* lisp/calc/calc-graph.el (calc-graph-set-styles): Use `symbol-value`
rather than `eval.`
(calc-graph-delete-temps, calc-graph-set-styles): Use ignore-errors.

* lisp/calc/calc-macs.el (calc-with-trail-buffer): Add artificial use
of `save-buf` to silence compiler warnings in all the cases where
`body` doesn't make use of it.

* lisp/calc/calc-math.el (math-largest-emacs-expt)
(math-smallest-emacs-expt, math-use-emacs-fn): Use ignore-errors.

* lisp/calc/calc-mode.el (calc-total-algebraic-mode): Remove "P" from
interactive spec since it's not used anyway.

* lisp/calc/calc-rewr.el (calc-match): Simplify.

* lisp/calc/calc.el (calc-buffer): Give it a global nil value,
so it's automatically declared dynbound in any file that requires `calc`.
(calcDigit-nondigit): Adjust accordingly.

* lisp/calc/calcalg2.el (calcFunc-table): Declare `var-dummy` as dynbound.
(math-scan-for-limits): Comment out dead code.

* lisp/calc/calcalg3.el (math-general-fit): Declare `var-YVAL` and
`var-YVALX` as dynbound.

Run "TZ=UTC0 admin/update-copyright $(git ls-files)".

Run 'TZ=UTC0 admin/update-copyright $(git ls-files)'.

Run admin/update-copyright.