d: change the return value of yylex from int to TokenKind

* data/skeletons/lalr1.d: Change the return value.
* examples/d/calc/calc.y, examples/d/simple/calc.y: Adjust.
* tests/scanner.at: Adjust.
* tests/calc.at (_AT_DATA_CALC_Y(d)): New, extracted from...
(_AT_DATA_CALC_Y(c)): here.
The two grammars have been sufficiently different to be separated.
Still trying to be them together results in a maintenance burden.  For
the same reason, instead of specifying the results for D and for the
rest, compute the expected results with D from the regular case.

data/skeletons/lalr1.d

@@ -68,7 +68,7 @@ public interface Lexer
    * to the next token and prepares to return the semantic value
    * ]b4_locations_if([and beginning/ending positions ])[of the token.
    * @@return the token identifier corresponding to the next token. */
-  int yylex ();
+  TokenKind yylex ();
 
   /**
    * Entry point for error reporting.  Emits an error
@@ -272,7 +272,7 @@ b4_user_union_members
       yyDebugStream.writeln (s);
   }
 ]])[
-  private final int yylex () {
+  private final TokenKind yylex () {
     return yylexer.yylex ();
   }