Fix inserting an element of wxArrayString itself back into it.

Do the insertion/addition before deallocating the old memory to allow things
like array.Add(array[0]) to work correctly.

Closes #2290.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76909 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/arrays/arrays.cpp

@@ -346,6 +346,10 @@ void ArraysTestCase::wxStringArrayTest()
     a5.resize(3);
     CPPUNIT_ASSERT_EQUAL( 3, a5.size() );
     CPPUNIT_ASSERT_EQUAL( "Foo", a5[2] );
+
+    wxArrayString a6;
+    a6.Add("Foo");
+    a6.Insert(a6[0], 1, 100);
 }
 
 void ArraysTestCase::SortedArray()