Emulate exact behaviour on lists with IntStr/NumStr

First check numerically, if they're the same, then compare as strings.

src/core.c/Rakudo/Sorting.pm6

@@ -30,11 +30,15 @@ my class Rakudo::Sorting {
           for       => "as a value when sorting",
         ).throw
     }
-    multi sub compare(IntStr:D $a, IntStr:D $b) is raw { nqp::cmp_I($a,$b) }
-    multi sub compare(   Int:D $a,    Int:D $b) is raw { nqp::cmp_I($a,$b) }
-    multi sub compare(   Str:D $a,    Str:D $b) is raw { nqp::cmp_s($a,$b) }
-    multi sub compare(NumStr:D $a, NumStr:D $b) is raw { nqp::cmp_n($a,$b) }
-    multi sub compare(   Num:D $a,    Num:D $b) is raw { nqp::cmp_n($a,$b) }
+    multi sub compare(IntStr:D $a, IntStr:D $b) is raw {
+        nqp::cmp_I($a,$b) || nqp::cmp_s($a,$b)
+    }
+    multi sub compare(NumStr:D $a, NumStr:D $b) is raw {
+        nqp::cmp_n($a,$b) || nqp::cmp_s($a,$b)
+    }
+    multi sub compare(Int:D $a, Int:D $b) is raw { nqp::cmp_I($a,$b) }
+    multi sub compare(Str:D $a, Str:D $b) is raw { nqp::cmp_s($a,$b) }
+    multi sub compare(Num:D $a, Num:D $b) is raw { nqp::cmp_n($a,$b) }
     multi sub compare(\a, \b) { a cmp b }
 
     # https://en.wikipedia.org/wiki/Merge_sort#Bottom-up_implementation