Fix std::vector<> Java typemaps for primitive types

For such types, the generated proxy class inherited from
java.util.AbstractSet<BoxedType<T>> (where BoxedType<T> is "Integer",
for example, when T is "int"), but defined an overloaded add() taking T,
instead of overriding the base class virtual add() taking BoxedType<T>,
resulting in an exception being thrown whenever add() was called during
run-time.

Extend Java unit test to bring it to parity with C# one added in the
previous commit.

See #1568.

Examples/test-suite/java/li_std_set_runme.java

@@ -77,5 +77,14 @@ public class li_std_set_runme {
     checkThat(fooSet.isEmpty());
     checkThat(fooSet.add(new Foo(17)));
     checkThat(fooSet.size() == 1);
+
+    // And a set of primitive type.
+    java.util.AbstractSet<Integer> intSet = new IntSet();
+    checkThat(intSet.isEmpty());
+    checkThat(intSet.add(17));
+    checkThat(!intSet.add(17));
+    checkThat(intSet.size() == 1);
+    checkThat(intSet.add(289));
+    checkThat(intSet.size() == 2);
   }
 }

Examples/test-suite/li_std_set.i

@@ -40,10 +40,7 @@
         };
     %}
 
-    // This one doesn't work in Java correctly yet.
-#ifdef SWIGCSHARP
     %template(IntSet) std::set<int>;
-#endif
     %template(StringSet) std::set<std::string>;
     %template(FooSet) std::set<Foo>;
 #endif

Lib/java/std_set.i

@@ -57,6 +57,10 @@ class set {
     return sizeImpl();
   }
 
+  public boolean add($typemap(jboxtype, T) key) {
+    return addImpl(key);
+  }
+
   public boolean addAll(java.util.Collection<? extends $typemap(jboxtype, T)> collection) {
     boolean didAddElement = false;
     for (java.lang.Object object : collection) {
@@ -172,7 +176,7 @@ class set {
       %fragment("SWIG_SetSize");
 
       // Returns whether item was inserted.
-      bool add(const T& key) {
+      bool addImpl(const T& key) {
         return self->insert(key).second;
       }