lib/systems: Add uClibc just like MUSL

lib/systems/default.nix

@@ -29,6 +29,7 @@ rec {
         /**/ if final.isDarwin              then "libSystem"
         else if final.isMinGW               then "msvcrt"
         else if final.isMusl                then "musl"
+        else if final.isUClibc              then "uclibc"
         else if final.isAndroid             then "bionic"
         else if final.isLinux /* default */ then "glibc"
         # TODO(@Ericson2314) think more about other operating systems

lib/systems/inspect.nix

@@ -36,6 +36,7 @@ rec {
 
     isAndroid      = [ { abi = abis.android; } { abi = abis.androideabi; } ];
     isMusl         = with abis; map (a: { abi = a; }) [ musl musleabi musleabihf ];
+    isUClibc       = with abis; map (a: { abi = a; }) [ uclibc uclibceabi uclibceabihf ];
 
     isKexecable    = map (family: { kernel = kernels.linux; cpu.family = family; })
                        [ "x86" "arm" "aarch64" "mips" ];

lib/systems/parse.nix

@@ -193,6 +193,9 @@ rec {
     musleabi = {};
     musleabihf = {};
     musl = {};
+    uclibceabihf = {};
+    uclibceabi = {};
+    uclibc = {};
 
     unknown = {};
   };