bootstrap-tools-cross, release-cross: add various musl entries

pkgs/stdenv/linux/make-bootstrap-tools-cross.nix

···
   };
 
 in with (import ../../../lib).systems.examples; {
-  armv5tel  = make sheevaplug;
-  scaleway  = make scaleway-c1;
-  pogoplug4 = make pogoplug4;
-  armv6l    = make raspberryPi;
-  armv7l    = make armv7l-hf-multiplatform;
-  aarch64   = make aarch64-multiplatform;
-  musl      = make musl64;
+  armv5tel   = make sheevaplug;
+  scaleway   = make scaleway-c1;
+  pogoplug4  = make pogoplug4;
+  armv6l     = make raspberryPi;
+  armv7l     = make armv7l-hf-multiplatform;
+  aarch64    = make aarch64-multiplatform;
+  x86_64-musl  = make musl64;
+  i686-musl    = make musl32;
+  armv6l-musl  = make muslpi;
+  aarch64-musl = make aarch64-multiplatform-musl;
 }

pkgs/top-level/release-cross.nix

···
   android = mapTestOnCross lib.systems.examples.aarch64-multiplatform (linuxCommon // {
   });
 
-  musl = mapTestOnCross lib.systems.examples.musl64 linuxCommon;
+  x86_64-musl = mapTestOnCross lib.systems.examples.musl64 linuxCommon;
+  rpi-musl = mapTestOnCross lib.systems.examples.muslpi  (linuxCommon // {
+    vim = nativePlatforms;
+    unzip = nativePlatforms;
+    ddrescue = nativePlatforms;
+    lynx = nativePlatforms;
+    patchelf = nativePlatforms;
+    buildPackages.binutils = nativePlatforms;
+    mpg123 = nativePlatforms;
+  });
 
   /* Cross-built bootstrap tools for every supported platform */
   bootstrapTools = let