java: clean up the definition of token kinds

From

    public interface Lexer {
      /* Token kinds.  */
      /** Token number, to be returned by the scanner.  */
      static final int YYEOF = 0;
      /** Token number, to be returned by the scanner.  */
      static final int YYERRCODE = 256;
      /** Token number, to be returned by the scanner.  */
      static final int YYUNDEF = 257;
      /** Token number, to be returned by the scanner.  */
      static final int BANG = 258;
    ...
      /** Deprecated, use b4_symbol(0, id) instead.  */
      public static final int EOF = YYEOF;

to

    public interface Lexer {
      /* Token kinds.  */
      /** Token "end of file", to be returned by the scanner.  */
      static final int YYEOF = 0;
      /** Token error, to be returned by the scanner.  */
      static final int YYerror = 256;
      /** Token "invalid token", to be returned by the scanner.  */
      static final int YYUNDEF = 257;
      /** Token "!", to be returned by the scanner.  */
      static final int BANG = 258;
    ...
      /** Deprecated, use YYEOF instead.  */
      public static final int EOF = YYEOF;

* data/skeletons/java.m4 (b4_token_enum): Display the symbol's tag in
comment.
* data/skeletons/lalr1.java: Address overquotation issue.
* examples/java/calc/Calc.y, examples/java/simple/Calc.y: Use YYEOF,
not EOF.

examples/java/calc/Calc.y

@@ -150,7 +150,7 @@ class CalcLexer implements Calc.Lexer {
     end.set(reader.getPosition());
     switch (ttype) {
     case StreamTokenizer.TT_EOF:
-      return EOF;
+      return YYEOF;
     case StreamTokenizer.TT_EOL:
       end.line += 1;
       end.column = 0;

examples/java/simple/Calc.y

@@ -93,7 +93,7 @@ class CalcLexer implements Calc.Lexer {
     int ttype = st.nextToken();
     switch (ttype) {
     case StreamTokenizer.TT_EOF:
-      return EOF;
+      return YYEOF;
     case StreamTokenizer.TT_EOL:
       return (int) '\n';
     case StreamTokenizer.TT_WORD: