[REVIEW][3-5] gcc 4.7 UNO bridges fixes

[Michael Stahl]

so it seems that the C++ UNO bridges, when built with gcc 4.7, crash and
burn in the bridges test in testtools.

fortunately Stephan has fixed this problem on master, at least as far as
i can see, applying the attached patches in a x86_64 --enable-dbgutil
build gives me a nicely working office that passes all subsequent tests.

so, i guess it would make sense to put these into libreoffice-3-5.