CVE-2015-5276

Note that upstream revision 227687 is incomplete/incorrect. See
msg01050.html for a more complete patch that is undergoing review.
In gcc-4.7 through gcc-4.8, the code in question exists at
libstdc++-v3/include/tr1/random.h and libstdc++-v3/include/bits/random.h
In gcc-4.4, the code in question exists at
libstdc++-v3/include/tr1_impl/random

Note that for versions where the random_device() code in
question is in a header file, means that it's compiled into the
binaries built against libstdc++, which would need to be rebuilt to
get the fixed version.
upstream commits (so far) are listed under gcc-snapshots
package. Corresponding git commits are:
84bb4e67d45a8921cedd2ef64fe3cffd9ee72f44
8efb09c4325785a5e7d11d05c5aadc74d2a49887
fd16f36d1986fbbb9f802b3649e543f3f41227ea
gcc-opt is just a wrapper around gcc, not affected