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.

tests/actions.at

@@ -1385,7 +1385,6 @@ Entering state 0
 Stack now 0
 Reducing stack by rule 1 (line 49):
 -> $$ = nterm start (1.1: <]]kind[[> for 'S' @ 1)
-Stack now 0
 Entering state 1
 Stack now 0 1
 Reading a token
@@ -1649,22 +1648,18 @@ Entering state 0
 Stack now 0
 Reducing stack by rule 1 (line 30):
 -> $$ = nterm $@1 (: )
-Stack now 0
 Entering state 2
 Stack now 0 2
 Reducing stack by rule 2 (line 31):
 -> $$ = nterm @2 (: 2)
-Stack now 0 2
 Entering state 4
 Stack now 0 2 4
 Reducing stack by rule 3 (line 32):
 -> $$ = nterm @3 (: 3)
-Stack now 0 2 4
 Entering state 5
 Stack now 0 2 4 5
 Reducing stack by rule 4 (line 33):
 -> $$ = nterm @4 (: 4)
-Stack now 0 2 4 5
 Entering state 6
 Stack now 0 2 4 5 6
 Reading a token

tests/c++.at

@@ -658,14 +658,12 @@ Reducing stack by rule 1 (line 34):
    $1 = token NUMBER (1)
 -> $$ = nterm expr (10)
 destroy: 1
-Stack now 0
 Entering state 2
 Stack now 0 2
 Reading a token
 Next token is token NUMBER (30)
 Reducing stack by rule 2 (line 35):
 -> $$ = nterm @1 (20)
-Stack now 0 2
 Entering state 4
 Stack now 0 2 4
 Next token is token NUMBER (30)
@@ -681,7 +679,6 @@ expr: 10 20 30
 destroy: 30
 destroy: 20
 destroy: 10
-Stack now 0
 Entering state 2
 Stack now 0 2
 Reading a token

tests/calc.at

@@ -922,7 +922,7 @@ _AT_CHECK_CALC([$1],
 2^2^3 = 256
 (2^2)^3 = 64],
 [[final: 64 12 0]],
-               [1111])
+               [1017])
 
 # Some syntax errors.
 _AT_CHECK_CALC_ERROR([$1], [1], [1 2],

tests/regression.at

@@ -963,7 +963,6 @@ Entering state 0
 Stack now 0
 Reducing stack by rule 1 (line 20):
 -> $$ = nterm start ()
-Stack now 0
 Entering state 1
 Stack now 0 1
 Reading a token