* src/eval.c (Finternal_delete_indirect_variable): Add function.
* lisp/loadhist.el (loadhist-unload-element): Use it for variable
aliases.
* test/src/eval-tests.el (eval-tests--internal-delete-indirect-variable):
Test function `internal-delete-indirect-variable'.
* test/lisp/loadhist-tests.el (loadhist-test-unload-feature-alias):
* test/lisp/loadhist-resources/loadhist--alias.el: Test unloading of
features that define variable aliases.  (Bug#76748)

* configure.ac (ALIGNOF_INT, ALIGNOF_LONG, ALIGNOF_LONG_LONG):
New variables.
(emacs_cv_alignas_unavailable): Define if alignas and structure
alignment primitives are unavailable.  In such an environment,
the MSB tagging scheme must be enabled, as must the GNU malloc.

* msdos/sed2v2.inp: Adjust correspondingly.

* src/alloc.c (union emacs_align_type): Remove types which
contain flexible array members.  The address of a field
subsequent to an aggregate with flexible array members cannot
validly be taken.
(mark_memory) [!USE_LSB_TAG && !WIDE_EMACS_INT]: Strip type bits
before scanning memory.

* src/emacs.c (main):

* src/eval.c (Fautoload_do_load):

* src/fns.c (Frequire): Rename a number of illogically named
fields.

* src/lisp.h (ALIGNOF_EMACS_INT): Define to the natural
alignment of EMACS_INT.
(IDEAL_GCALIGNMENT): New macro.
(USE_LSB_TAG): Disable if no alignment specifiers are available,
WIDE_EMACS_INT is undefined, and the natural alignment of
EMACS_INT falls short of LSB tagging's requirements.
(gflags): Rename illogically named fields and don't define them
as bitfields, which runs afoul of certain compiler issues.
(will_dump_p, will_bootstrap_p, will_dump_with_pdumper_p)
(dumped_with_pdumper_p): Adjust accordingly.

* src/pdumper.c (VM_SUPPORTED): Define to 0 when !USE_LSB_TAG.
It is better to read dump files into the heap by hand than to be
supplied with an address that is not representable.
(_dump_object_start_pseudovector): Rename to
dump_object_start_pseudovector, to avoid encroaching on reserved
names.
(START_DUMP_PVEC): Adjust correspondingly.
(dump_mmap_contiguous_vm): Preserve errno around failure
cleanup.
(dump_bitset_bit_set_p): Work around certain compiler issues.
(pdumper_load) [!USE_LSB_TAG]: Reject dump file allocations
that are not representable as Lisp_Objects.

Tested on i386-unknown-solaris2.10, sparc-sun-solaris2.10.

* src/eval.c (internal_lisp_condition_case): Omit an unnecessary
‘volatile’ and an unnecessary pointer-to-volatile local var.
Perhaps these were needed in previous versions of Emacs, or to
pacify older versions of GCC when using --enable-gcc-warnings,
but they are not needed to pacify current GCC.

Since the introduction of the 'calln' macro, the 'call1', 'call2', ...,
'call8' macros are just aliases for the former.  This is slightly
misleading and potentially unhelpful.  The number of arguments N can
also easily go out-of-synch with the used alias callN.  There is no
reason not to replace these aliases with using 'calln' directly.

To reduce the risk for mistakes, the tool Coccinelle was used to make
these changes.  See <https://coccinelle.gitlabpages.inria.fr/website/>.

* src/alloc.c, src/androidvfs.c, src/androidfns.c, src/buffer.c:
* src/callint.c, src/callproc.c, src/casefiddle.c, src/charset.c:
* src/chartab.c, src/cmds.c, src/coding.c, src/composite.c:
* src/data.c, src/dbusbind.c, src/dired.c, src/doc.c:
* src/emacs.c, src/eval.c, src/fileio.c, src/filelock.c:
* src/fns.c, src/frame.c, src/gtkutil.c, src/haikufns.c:
* src/haikumenu.c, src/image.c, src/insdel.c, src/intervals.c:
* src/keyboard.c, src/keymap.c, src/lisp.h, src/lread.c:
* src/minibuf.c, src/nsfns.m, src/nsselect.m, src/pgtkfns.c:
* src/pgtkselect.c, src/print.c, src/process.c, src/sort.c:
* src/syntax.c, src/textconv.c, src/textprop.c, src/undo.c:
* src/w32fns.c, src/window.c, src/xfaces.c, src/xfns.c:
* src/xmenu.c, src/xselect.c, src/xterm.c:
Replace all uses of 'call1', 'call2', ..., 'call8' with 'calln'.

* src/bytecode.c (bcall0):
* src/comp.c (bcall0):
* src/eval.c (apply1):
* src/lisp.h (call0):
* src/thread.c (invoke_thread_function): Use calln instead of calling
Ffuncall directly.

* admin/coccinelle/calln.cocci: New semantic patch.

* src/callint.c (read_file_name):
* src/comp.c (CALL0I, CALL1I, CALL2I, CALL4I, declare_imported_func):
* src/data.c (Ffset, notify_variable_watchers):
* src/eval.c (Ffuncall_with_delayed_message):
* src/keymap.c (Fdescribe_buffer_bindings):
* src/minibuf.c (Fread_buffer, Fcompleting_read):
* src/pdumper.c (Fdump_emacs_portable):
* src/print.c (print_vectorlike_unreadable):
* src/treesit.c (treesit_traverse_match_predicate)
(treesit_build_sparse_tree): Prefer calln to CALLN.