Silence compiler by adding cosmetic virtual destructors.

[SVN r41549]

test/bienstman1.cpp

@@ -11,7 +11,7 @@ struct A {};
 
 struct V 
 {
-
+ virtual ~V() {}; // silence compiler warningsa
  virtual void f() = 0;
 
  const A* inside() {return &a;}

test/bienstman3.cpp

@@ -7,6 +7,7 @@
 
 struct V 
 {
+ virtual ~V() {}; // silence compiler warningsa
  virtual void f() = 0;
 };
 

test/implicit.cpp

@@ -24,6 +24,7 @@ X make_x(int n) { return X(n); }
 struct bar {};
 struct foo
 {
+    virtual ~foo() {}; // silence compiler warnings
     virtual void f() = 0;
     operator bar() const { return bar(); }
 };

test/pointer_vector.cpp

@@ -10,6 +10,7 @@ using namespace boost::python;
 class Abstract
 {
 public:   
+    virtual ~Abstract() {}; // silence compiler warningsa
     virtual std::string    f() =0;
 };