Add links for casting array (literals)

Also make examples runnable.

Author: ntrel

spec/expression.dd

@@ -1074,6 +1074,7 @@ $(H3 $(LNAME2 cast_array, Arrays))
         as a type paint, with the array length adjusted to match any change in
         element size. If there's not a match, a runtime error is generated.)
 
+        $(SPEC_RUNNABLE_EXAMPLE_COMPILE
         ---
         import std.stdio;
 
@@ -1090,7 +1091,9 @@ $(H3 $(LNAME2 cast_array, Arrays))
             return 0;
         }
         ---
+        )
 
+    $(DDOC_SEE_ALSO $(RELATIVE_LINK2 cast_array_literal, Casting array literals).)
 
 $(H3 $(LNAME2 cast_static_array, Static Arrays))
 
@@ -1618,11 +1621,14 @@ $(GNAME ArrayLiteral):
         }
         ---
 
+$(H3 $(LNAME2 cast_array_literal, Casting))
+
     $(P When array literals are cast to another array type, each
         element of the array is cast to the new element type.
-        When arrays that are not literals are cast, the array is
+        When arrays that are not literals $(RELATIVE_LINK2 cast_array, are cast), the array is
         reinterpreted as the new type, and the length is recomputed:)
 
+        $(SPEC_RUNNABLE_EXAMPLE_RUN
         ---
         import std.stdio;
 
@@ -1641,6 +1647,7 @@ $(GNAME ArrayLiteral):
             writeln(rt);  // writes [257]
         }
         ---
+        )
 
         In other words, casting literal expression will change the literal type.