tests: remove useless prefix for EOF in D

* tests/calc.at (CALC_EOF): Rename as...
(EOF): this.
Since there is no risk of a clash with #define EOF here...

TODO

@@ -256,6 +256,9 @@ are.  Keep the same variable names.  If you change the wording in one place,
 do it in the others too.  In other words: make sure to keep the
 maintenance *simple* by avoiding any gratuitous difference.
 
+** CI
+Check when gdc and ldc.
+
 ** Documentation
 Write documentation about D support in doc/bison.texi.  Imitate the Java
 documentation.  You should be more succinct IMHO.

tests/calc.at

@@ -606,7 +606,7 @@ class CalcLexer(R) : Lexer
 
     // EOF.
     if (input.empty)
-      return TokenKind.]AT_TOKEN_PREFIX[CALC_EOF;
+      return TokenKind.]AT_TOKEN_PREFIX[EOF;
 
     // Numbers.
     if (input.front.isNumber)
@@ -666,7 +666,7 @@ m4_define([_AT_DATA_CALC_Y(d)],
 %printer { fprintf (yyo, "%d", $$); } <ival>;
 
 /* Bison Declarations */
-%token CALC_EOF 0 ]AT_TOKEN_TRANSLATE_IF([_("end of input")], ["end of input"])[
+%token EOF 0 ]AT_TOKEN_TRANSLATE_IF([_("end of input")], ["end of input"])[
 %token <ival> NUM   "number"
 %type  <ival> exp