error: rename the error token from YYERRCODE to YYerror

See https://lists.gnu.org/r/bison-patches/2020-04/msg00162.html.

* data/skeletons/bison.m4, data/skeletons/c.m4, data/skeletons/glr.cc,
* data/skeletons/lalr1.java, doc/bison.texi,
* examples/c/bistromathic/parse.y, src/scan-gram.l, src/symtab.c
(YYERRCODE): Rename as...
(YYerror): this.
Adjust dependencies.

tests/calc.at

@@ -226,7 +226,7 @@ read_integer (]AT_YYLEX_FORMALS[)
       fprintf (stderr, "%d.%d: ",
                AT_LOC_FIRST_LINE, AT_LOC_FIRST_COLUMN);])[
       fputs ("syntax error: invalid character: '#'\n", stderr);
-      return ]AT_TOKEN_PREFIX[]AT_API_PREFIX[ERRCODE;
+      return ]AT_TOKEN_PREFIX[]AT_API_PREFIX[error;
     }
 
   /* Return single chars. */
@@ -339,7 +339,7 @@ class CalcLexer(R) : Lexer
     if (c == '#')
       {
         stderr.writeln (]AT_LOCATION_IF([location, ": ", ])["syntax error: invalid character: '#'");
-        return TokenKind.YYERRCODE;
+        return TokenKind.YYerror;
       }
 
     return c;
@@ -405,7 +405,7 @@ m4_define([AT_CALC_YYLEX(java)],
         return yylex ();
       case '#':
         System.err.println(]AT_LOCATION_IF([[start + ": " + ]])["syntax error: invalid character: '#'");
-        return YYERRCODE;
+        return YYerror;
       default:
         return tkind;
       }
@@ -1025,9 +1025,9 @@ _AT_CHECK_CALC_ERROR([$1], [0], [(* *) + (*) + (*)],
 ]AT_JAVA_IF([1.16-1.17], [1.16])[: syntax error on token ['*'] (expected: [number] ['-'] ['('] ['!'])]])
 
 
-# YYERRCODE.
-# ---------
-# Check that returning YYERRCODE from the scanner properly enters
+# YYerror.
+# --------
+# Check that returning YYerror from the scanner properly enters
 # error-recovery without issuing a second error message.
 
 _AT_CHECK_CALC_ERROR([$1], [0], [(#) + (#) = 2222],