configure: Drop feature for randomly disabling/enabling components

This feature was never used for anything.

configure

@@ -342,14 +342,6 @@ Developer options (useful when working on Libav itself):
                            used only for debugging purposes)
   --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                            should be used only for debugging purposes)
-  --enable-random          randomly enable/disable components
-  --disable-random
-  --enable-random=LIST     randomly enable/disable specific components or
-  --disable-random=LIST    component groups. LIST is a comma-separated list
-                           of NAME[:PROB] entries where NAME is a component
-                           (group) and PROB the probability associated with
-                           NAME (default 0.5).
-  --random-seed=VALUE      seed value for --enable/disable-random
   --disable-valgrind-backtrace do not print a backtrace under Valgrind
                            (only applies to --disable-optimizations builds)
   --ignore-tests=TESTS     comma-separated list (without "fate-" prefix
@@ -1855,7 +1847,6 @@ CMDLINE_SET="
     optflags
     pkg_config
     pkg_config_flags
-    random_seed
     samples
     sysinclude
     sysroot
@@ -2794,27 +2785,6 @@ show_list() {
     exit 0
 }
 
-rand_list(){
-    IFS=', '
-    set -- $*
-    unset IFS
-    for thing; do
-        comp=${thing%:*}
-        prob=${thing#$comp}
-        prob=${prob#:}
-        is_in ${comp} $COMPONENT_LIST && eval comp=\$$(toupper ${comp%s})_LIST
-        echo "prob ${prob:-0.5}"
-        printf '%s\n' $comp
-    done
-}
-
-do_random(){
-    action=$1
-    shift
-    random_seed=$(awk "BEGIN { srand($random_seed); print srand() }")
-    $action $(rand_list "$@" | awk "BEGIN { srand($random_seed) } \$1 == \"prob\" { prob = \$2; next } rand() < prob { print }")
-}
-
 for opt do
     optval="${opt#*=}"
     case "$opt" in
@@ -2846,14 +2816,6 @@ for opt do
             map 'eval unset \${$(toupper ${v%s})_LIST}' $COMPONENT_LIST
             disable $LIBRARY_LIST $PROGRAM_LIST doc
         ;;
-        --enable-random|--disable-random)
-            action=${opt%%-random}
-            do_random ${action#--} $COMPONENT_LIST
-        ;;
-        --enable-random=*|--disable-random=*)
-            action=${opt%%-random=*}
-            do_random ${action#--} $optval
-        ;;
         --enable-*=*|--disable-*=*)
             eval $(echo "${opt%%=*}" | sed 's/--/action=/;s/-/ thing=/')
             is_in "${thing}s" $COMPONENT_LIST || die_unknown "$opt"
@@ -5287,9 +5249,6 @@ echo "shared                    ${shared-no}"
 echo "network support           ${network-no}"
 echo "threading support         ${thread_type-no}"
 echo "safe bitstream reader     ${safe_bitstream_reader-no}"
-test -n "$random_seed" &&
-    echo "random seed               ${random_seed}"
-echo
 
 echo "External libraries:"
 print_enabled '' $EXTERNAL_LIBRARY_LIST | print_3_columns