busybox shell: enable various useful/expected features

Matches changes made in nixpkgs:
https://github.com/NixOS/nixpkgs/pull/34628

release-common.nix

@@ -6,10 +6,22 @@ rec {
     enableStatic = true;
     enableMinimal = true;
     extraConfig = ''
+      CONFIG_FEATURE_FANCY_ECHO y
+      CONFIG_FEATURE_SH_MATH y
+      CONFIG_FEATURE_SH_MATH_64 y
+
       CONFIG_ASH y
-      CONFIG_ASH_ECHO y
-      CONFIG_ASH_TEST y
       CONFIG_ASH_OPTIMIZE_FOR_SIZE y
+
+      CONFIG_ASH_ALIAS y
+      CONFIG_ASH_BASH_COMPAT y
+      CONFIG_ASH_CMDCMD y
+      CONFIG_ASH_ECHO y
+      CONFIG_ASH_GETOPTS y
+      CONFIG_ASH_INTERNAL_GLOB y
+      CONFIG_ASH_JOB_CONTROL y
+      CONFIG_ASH_PRINTF y
+      CONFIG_ASH_TEST y
     '';
   };