Pacify --enable-gcc-warnings when HYBRID_MALLOC

Pacify --enable-gcc-warnings when HYBRID_MALLOC

* src/buffer.c (init_buffer):
* src/emacs.c (main):
* src/xsmfns.c (smc_save_yourself_CB, x_session_initialize):
Use emacs_get_current_dir_name, not get_current_dir_name.
* src/conf_post.h (aligned_alloc) [HYBRID_MALLOC && emacs]: New macro.
(HYBRID_GET_CURRENT_DIR_NAME, get_current_dir_name): Remove.
* src/emacs.c: Include "sheap.h".
(report_sheap_usage): Remove decl.
(Fdump_emacs) [HYBRID_MALLOC]: Report usage directly.
Don't assume ptrdiff_t can be printed as int.
* src/gmalloc.c [HYBRID_MALLOC]:
Include "sheap.h" rather than declaring its contents by hand.
(get_current_dir_name, gget_current_dir_name)
(hybrid_get_current_dir_name): Remove.
(emacs_abort): Remove duplicate decl.
(aligned_alloc): Undef, like malloc etc.
(ALLOCATED_BEFORE_DUMPING): Now a static function, not a macro.
Make it a bit more efficient.
(malloc_find_object_address): Remove unused decl.
(enum mcheck_status, mcheck, mprobe, mtrace, muntrace, struct mstats)
(mstats, memory_warnings): Declare only if GC_MCHECK.
* src/lisp.h (emacs_get_current_dir_name):
New decl, replacing get_current_dir_name.
* src/sheap.c: Include sheap.h first.
(STATIC_HEAP_SIZE): Remove; now in sheap.h.
(debug_sheap): Now static.
(bss_sbrk_buffer_end): Remove; no longer used.
(bss_sbrk_ptr): Now static and private.
(bss_sbrk_did_unexec): Now bool.
(BLOCKSIZE): Remove, to avoid GCC warning about its not being used.
(bss_sbrk): Don't treat request_size 0 as special, since the code
works without this being a special case.
Avoid overflow if request size exceeds INT_MAX.
(report_sheap_usage): Remove; now done in emacs.c.
* src/sheap.h: New file.
* src/sysdep.c (get_current_dir_name): Remove macro.
Include "sheap.h".
(emacs_get_current_dir_name): Rename function from
get_current_dir_name.  Handle HYBRID_MALLOC here;
this is simpler.
(Bug#22086)