* src/comp.h, src/thread.h: Add INLINE_HEADER_BEGIN and
INLINE_HEADER_END, since it uses INLINE.
* src/emacs.c: Include these two files.

The C standard does not allow size-zero arrays, so redo struct
Lisp_Subr to not use size-zero arrays when native compilation is
not being used.  Formerly, the code was using size-zero arrays (a
GNU C extension) to avoid using memory unnecessarily when
HAVE_NATIVE_COMP is not defined.  Replace this hack with the
more-traditional hack of putting the relevant members inside
‘#ifdef HAVE_NATIVE_COMP’.
* src/alloc.c (cleanup_vector, mark_object):
* src/comp.c (make_subr):
* src/data.c (Fsubr_native_lambda_list, Fsubr_native_comp_unit):
* src/eval.c (init_eval_once, funcall_lambda):
* src/lisp.h (SUBR_NATIVE_COMPILEDP, SUBR_NATIVE_COMPILED_DYNP)
(SUBR_TYPE):
* src/lread.c (Fload):
Conditionally compile with ‘#ifdef HAVE_NATIVE_COMP’ instead of
with ‘if (NATIVE_COMP_FLAG)’.  Redo members like native_comp_u[0]
to be plain native_comp_u.  Put all uses of these members inside
‘#ifdef HAVE_NATIVE_COMP’.
* src/lisp.h (struct Lisp_Subr): Members native_comp_u,
native_c_name, lambda_list, type are now all ifdeffed out if
HAVE_NATIVE_COMP is not defined, instead of being size-zero
arrays.  All uses changed.
* src/pdumper.c (dump_subr, dump_cold_native_subr)
(dump_do_dump_relocation):
* src/comp.h (NATIVE_COMP_FLAG): Remove; no longer needed.

* src/emacs.c (real_filename, set_invocation_vars)
(init_vars_for_load): Functions deleted; callers adjusted.
(init_cmdargs): Put back all the code which was extracted into
set_invocation_vars.
(load_pdump_find_executable): Make sure the return value has any
symlinks in it expanded.
(load_pdump): Accept only 2 arguments, not 3.  Determine both the
file name of the Emacs executable and of the dump file in
synchronized manner, so that if we decided to look for the dump
file in its hardcoded installation directory, the directory of the
Emacs executable will also be where we expect it to be installed.
Pass only 2 arguments to pdumper_load.  (Bug#47800)  (Bug#44128)
* src/pdumper.c (dump_do_dump_relocation): Use emacs_execdir
instead of Vinvocation_directory to produce absolute file names of
*.eln files that are recorded in the pdumper file.  Pass the full
.eln file name to fixup_eln_load_path.
(pdumper_set_emacs_execdir) [HAVE_NATIVE_COMP]: New function.
(pdumper_load) [HAVE_NATIVE_COMP]: Call pdumper_set_emacs_execdir.
* src/comp.c (fixup_eln_load_path): Use Fsubstring_no_properties
instead of Fsubstring.  No need to cons a file name, as the caller
already did that.  Use explicit const string to avoid "magic"
values.

* lisp/startup.el (normal-top-level): Use expand-file-name instead
of concat.  Decode comp-eln-load-path and expand-file-name its
members.

* src/alloc.c (cleanup_vector): Call unload_comp_unit.
* src/comp.c (unload_comp_unit): New function.

	* lisp/emacs-lisp/comp.el (comp-emit-for-top-level): Synthesize
	'top_level_run' so it returns the last value returned by
	`comp--register-subr'.
	* src/comp.c (load_comp_unit): Return what 'top_level_run'
	returns.
	(Fnative_elisp_load): Return what 'load_comp_unit' returns.
	* src/comp.h (load_comp_unit): Update signature.

When recompiling remove the corresponding stale elns found in the
`comp-eln-load-path'.

When removing a package remove the corresponding elns too.

On Windows both of these are performed only when possible, when it's
not the file is renamed as .eln.old and a last attempt to remove this
is performed closing the Emacs session.  When a file being deleted was
loaded by multiple Emacs sessions the last one being closed should
delete it.

	* lisp/emacs-lisp/comp.el (comp-clean-up-stale-eln): New function.
	(comp-delete-or-replace-file): Rename from
	`comp--replace-output-file' and update so it can be used for
	replacing or deleting shared libs safetly.

	* lisp/emacs-lisp/package.el (package--delete-directory): When
	native compiled just call `comp-clean-up-stale-eln' for each
	eln file we want to clean-up.

	* src/alloc.c (cleanup_vector): Call directly the dynlib_close.

	* src/comp.c (syms_of_comp): Update for comp_u->cfile removal.
	Make 'all_loaded_comp_units_h' key-value weak as now the key will
	be the filename.
	(load_comp_unit): Register the compilation unit only when the load
	is fully completed.
	(register_native_comp_unit): Make the key of
	all_loaded_comp_units_h the load filename.
	(eln_load_path_final_clean_up): New function.
	(dispose_comp_unit)
	(finish_delayed_disposal_of_comp_units)
	(dispose_all_remaining_comp_units)
	(clean_package_user_dir_of_old_comp_units): Remove.
	(Fcomp__compile_ctxt_to_file): Update for
	`comp--replace-output-file' -> `comp-delete-or-replace-file'
	rename.

	* src/comp.h (dispose_comp_unit)
	(finish_delayed_disposal_of_comp_units)
	(dispose_all_remaining_comp_units)
	(clean_package_user_dir_of_old_comp_units): Remove.
	(eln_load_path_final_clean_up): Add.
	(struct Lisp_Native_Comp_Unit): Remove cfile field.

	* src/emacs.c (Fkill_emacs): Call 'eln_load_path_final_clean_up'.

	* src/pdumper.c (dump_do_dump_relocation): Do not set comp_u->cfile.