add generic header

include/ac/alloca.h

+/* Generic alloca.h */
+
+#ifndef _AC_ALLOCA_H
+#define _AC_ALLOCA_H
+
+/* AIX requires this to be the first thing in the file.  */
+#ifdef __GNUC__
+# define alloca __builtin_alloca
+#else
+# if HAVE_ALLOCA_H
+#  include <alloca.h>
+# else
+#  ifdef _AIX
+#pragma alloca
+#  else
+#   ifndef alloca /* predefined by HP cc +Olibcalls */
+char *alloca ();
+#   endif
+#  endif
+# endif
+#endif
+
+
+#endif /* _AC_ALLOCA_H */

include/ac/wait.h

+/* Generic wait.h */
+
+#ifndef _AC_WAIT_H
+#define _AC_WAIT_H
+
+#include <sys/types.h>
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
+#endif
+#ifndef WIFEXITED
+# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+
+#endif /* _AC_WAIT_H */