Bug#701082: gcc-4.7: gcc generates incorrect code with -O2 compiling libffi example

[Philip Ashmore <contact@philipashmore.com>]

This problem doesn't happen on Ubuntu or on a fresh squeeze install.
Then I realised I had gcc 4.4, 4.5 and 4.6 installed as well as 4.7 and 4.8.
With 4.4, 4.5 and 4.6, gcc -O2 -o ffi-test ffi-test.c works.
With 4.7 and 4.8 it segfaults instead of outputting "This is cool!".