conflicting libstdc++?

[Niclas Rosenvik <nros%NetBSD.org@localhost>]

I tried to build devel/cppcheck on NetBSD 6 and it fails due to that
gcc 4.5 is missing c++ nullptr. gcc 4.6 and above is needed for this.
Well I add GCC_REQD+=4.6 to Makefile and then it builds. But at the end
ld mentions that libstdc++.so.6 might conflict with libstdc++.so.7 that
is needed by tinyxml2.so.2 . Is there any way to fix this? 
Or can it just be ignored?

Regards,
Niclas Rosenvik