configure: remove checks for malloc.h and alloca()

Including <malloc.h>, especially if all you want is malloc(), has no
legitimate uses (on sane platforms at least). Remove the check for it,
and remove all uses in the code.

Remove unused check for alloca().

configure

@@ -1713,29 +1713,6 @@ if test "$_inttypes" = no ; then
 fi
 
 
-echocheck "malloc.h"
-_malloc=no
-header_check malloc.h && _malloc=yes
-if test "$_malloc" = yes ; then
-  def_malloc_h='#define HAVE_MALLOC_H 1'
-else
-  def_malloc_h='#define HAVE_MALLOC_H 0'
-fi
-echores "$_malloc"
-
-
-
-echocheck "alloca.h"
-_alloca=no
-statement_check alloca.h 'alloca(0)' && _alloca=yes
-if cc_check ; then
-  def_alloca_h='#define HAVE_ALLOCA_H 1'
-else
-  def_alloca_h='#undef HAVE_ALLOCA_H'
-fi
-echores "$_alloca"
-
-
 echocheck "mman.h"
 _mman=no
 statement_check sys/mman.h 'mmap(0, 0, 0, 0, 0, 0)' && _mman=yes
@@ -3074,10 +3051,6 @@ fi
 echores "$_openal"
 
 echocheck "ALSA audio"
-if test "$_alloca" != yes ; then
-  _alsa=no
-  res_comment="alloca missing"
-fi
 if test "$_alsa" = auto ; then
     _alsa=no
     if pkg_config_add "alsa >= 1.0.9" ; then
@@ -4346,8 +4319,6 @@ $def_dvdcss
 
 
 /* system headers */
-$def_alloca_h
-$def_malloc_h
 $def_mman_h
 $def_mman_has_map_failed
 $def_soundcard_h

libmpcodecs/vd_dmo.c

@@ -18,9 +18,6 @@
 
 #include "config.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>

libmpcodecs/vf.c

@@ -23,9 +23,6 @@
 #include <endian.h>
 
 #include "config.h"
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
 
 #include "mp_msg.h"
 #include "m_option.h"

libmpcodecs/vf_noise.c

@@ -28,10 +28,6 @@
 #include "mp_msg.h"
 #include "cpudetect.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "img_format.h"
 #include "mp_image.h"
 #include "vf.h"

libmpcodecs/vf_perspective.c

@@ -28,10 +28,6 @@
 #include "config.h"
 #include "mp_msg.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "libavutil/mem.h"
 
 #include "img_format.h"

libmpcodecs/vf_pp.c

@@ -26,10 +26,6 @@
 #include "mp_msg.h"
 #include "cpudetect.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "img_format.h"
 #include "mp_image.h"
 #include "vf.h"

libmpcodecs/vf_pp7.c

@@ -30,10 +30,6 @@
 #include "mp_msg.h"
 #include "cpudetect.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "libavutil/mem.h"
 
 #include "img_format.h"

libmpcodecs/vf_sab.c

@@ -27,10 +27,6 @@
 #include "config.h"
 #include "mp_msg.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "libavutil/avutil.h"
 #include "img_format.h"
 #include "mp_image.h"

libmpcodecs/vf_unsharp.c

@@ -28,10 +28,6 @@
 #include "mp_msg.h"
 #include "cpudetect.h"
 
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "img_format.h"
 #include "mp_image.h"
 #include "vf.h"

libmpdemux/video.c

@@ -21,9 +21,6 @@
 #include "config.h"
 
 #include <stdio.h>
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

sub/sub.c

@@ -24,9 +24,6 @@
 #include <libavutil/common.h>
 
 #include "config.h"
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
 
 #include "stream/stream.h"
 #include "stream/stream_dvdnav.h"