make: avo_alloca.h works around a very old Solaris bug, delete it

*** 32,42 ****
  
  /*
   * Included files
   */
  #include <sys/wait.h>                   /* WIFEXITED(status) */
! #include <avo/avo_alloca.h>             /* alloca() */
  
  #if defined(TEAMWARE_MAKE_CMN) || defined(MAKETOOL) /* tolik */
  #       include <avo/strings.h> /* AVO_STRDUP() */
  #if defined(DISTRIBUTED)
  #       include <dm/Avo_CmdOutput.h>
--- 32,42 ----
  
  /*
   * Included files
   */
  #include <sys/wait.h>                   /* WIFEXITED(status) */
! #include <alloca.h>             /* alloca() */
  
  #if defined(TEAMWARE_MAKE_CMN) || defined(MAKETOOL) /* tolik */
  #       include <avo/strings.h> /* AVO_STRDUP() */
  #if defined(DISTRIBUTED)
  #       include <dm/Avo_CmdOutput.h>