traces: don't print the stack before the gotos

The C, C++ and D skeletons used to show the stack right after popping
the stack during the reduction.  Now that the stack is printed after
reaching a new state, that has become useless:

    Entering state 1
    Stack now 0 1
    Reducing stack by rule 5 (line 83):
       $1 = token "number" (1)
    -> $$ = nterm exp (1)
    Stack now 0
    Entering state 8
    Stack now 0 8

Remove the "Stack now 0" line.

* data/skeletons/lalr1.cc, data/skeletons/lalr1.d,
* data/skeletons/lalr1.java, data/skeletons/yacc.c:
Here.

data/skeletons/lalr1.cc

@@ -993,7 +993,6 @@ b4_dollar_popdef])[]dnl
       YY_SYMBOL_PRINT ("-> $$ =", yylhs);
       yypop_ (yylen);
       yylen = 0;
-      YY_STACK_PRINT ();
 
       // Shift the result of the reduction.
       yypush_ (YY_NULLPTR, YY_MOVE (yylhs));

data/skeletons/lalr1.d

@@ -344,9 +344,6 @@ b4_user_union_members
 
     yystack.pop (yylen);
     yylen = 0;
-]b4_parse_trace_if([[
-    if (0 < yydebug)
-      yystack.print (yyDebugStream);]])[
 
     /* Shift the result of the reduction.  */
     yyn = yyr1_[yyn];

data/skeletons/lalr1.java

@@ -482,7 +482,6 @@ m4_define([b4_define_state],[[
 
     yystack.pop (yylen);
     yylen = 0;
-
     /* Shift the result of the reduction.  */
     int yystate = yyLRGotoState (yystack.stateAt (0), yyr1_[yyn]);
     yystack.push (yystate, yyval]b4_locations_if([, yyloc])[);

data/skeletons/yacc.c

@@ -1823,7 +1823,6 @@ yyreduce:
 
   YYPOPSTACK (yylen);
   yylen = 0;
-  YY_STACK_PRINT (yyss, yyssp);
 
   *++yyvsp = yyval;]b4_locations_if([
   *++yylsp = yyloc;])[