[Libreoffice] Fix build with gcc 4.5

[Ivan Timofeev]

Hello! I'm using gcc-4.5 and I've just got the following error while
compiling LibreOffice:

#pragma GCC diagnostic not allowed inside functions

The cause of error located in sal/inc/sal/types.h, line 469. It must
have "__GNUC_MINOR__ >= 6", I think.
You can make sure by comparing function "handle_pragma_diagnostic" at
http://gcc.gnu.org/viewcvs/branches/gcc-4_5-branch/gcc/c-pragma.c?view=markup
and at http://gcc.gnu.org/viewcvs/branches/gcc-4_6-branch/gcc/c-family/c-pragma.c?view=markup