Remove fallback symbol detection

Author: AA-Turner

configure

@@ -5386,21 +5386,8 @@ PKG_CHECK_MODULES([LIBLZMA], [liblzma], [have_liblzma=yes], [
   ])
 ])
 
-dnl zstd 1.4.5 added ZDICT_finalizeDictionary
-PKG_CHECK_MODULES([LIBZSTD], [libzstd >= 1.4.5], [have_libzstd=yes], [
-  WITH_SAVE_ENV([
-    CPPFLAGS="$CPPFLAGS $LIBZSTD_CFLAGS"
-    LIBS="$LIBS $LIBZSTD_LIBS"
-    AC_CHECK_HEADERS([zstd.h zdict.h], [
-      PY_CHECK_LIB([zstd], [ZDICT_finalizeDictionary],
-                   [have_libzstd=yes], [have_libzstd=no])
-    ], [have_libzstd=no])
-    AS_VAR_IF([have_libzstd], [yes], [
-      LIBZSTD_CFLAGS=${LIBZSTD_CFLAGS-""}
-      LIBZSTD_LIBS=${LIBZSTD_LIBS-"-lzstd"}
-    ])
-  ])
-])
+dnl zstd 1.4.5 stabilised ZDICT_finalizeDictionary
+PKG_CHECK_MODULES([LIBZSTD], [libzstd >= 1.4.5], [have_libzstd=yes], [have_libzstd=no])
 
 dnl PY_CHECK_NETDB_FUNC(FUNCTION)
 AC_DEFUN([PY_CHECK_NETDB_FUNC], [PY_CHECK_FUNC([$1], [@%:@include <netdb.h>])])

configure.ac

@@ -1630,18 +1630,12 @@
 /* Define to 1 if you have the 'writev' function. */
 #undef HAVE_WRITEV
 
-/* Define to 1 if you have the <zdict.h> header file. */
-#undef HAVE_ZDICT_H
-
 /* Define if the zlib library has inflateCopy */
 #undef HAVE_ZLIB_COPY
 
 /* Define to 1 if you have the <zlib.h> header file. */
 #undef HAVE_ZLIB_H
 
-/* Define to 1 if you have the <zstd.h> header file. */
-#undef HAVE_ZSTD_H
-
 /* Define to 1 if you have the '_getpty' function. */
 #undef HAVE__GETPTY