Remove redundant Haiku root library

The libroot on Haiku (C standard library) is linked in by default.

Author: petk

ext/opcache/config.m4

@@ -239,12 +239,12 @@ int main(void) {
   AC_MSG_RESULT([$have_shm_mmap_anon])
 
   dnl Check POSIX shared memory object operations and link required library as
-  dnl needed: rt (older Linux and Solaris <= 10), root (Haiku nightly), other
-  dnl systems have it in C library (newer Linux, illumos, Solaris 11.4, macOS,
-  dnl BSD-based systems, Haiku R1...).
+  dnl needed: rt (older Linux and Solaris <= 10). Most systems have it in the C
+  dnl standard library (newer Linux, illumos, Solaris 11.4, macOS, BSD-based
+  dnl systems...). Haiku has it in the root library, which is linked by default.
   LIBS_save="$LIBS"
   LIBS=
-  AC_SEARCH_LIBS([shm_open], [rt root],
+  AC_SEARCH_LIBS([shm_open], [rt],
     [AC_CACHE_CHECK([for mmap() using shm_open() shared memory support],
       [php_cv_shm_mmap_posix],
       [AC_RUN_IFELSE([AC_LANG_SOURCE([[