[Bug 38653] GCC 5.1 breaks -O2 optimization with 64-bit Wine

https://bugs.winehq.org/show_bug.cgi?id=38653

--- Comment #15 from Marcus Meissner  ---
For me even wineboot 64bit triggers a crash.

this seems to happen in dlls/setupapi/fakedll.c

adding 2 FIXME lines makes it work again, so there is weird optimization
between the memcpy and strcpys going on.

memcpy( new_buffer, manifest, arch.ptr - manifest );
                FIXME("after 1st memcpy\n");
                strcpy( new_buffer + (arch.ptr - manifest), current_arch);
                FIXME("after 2nd strcpy\n");
                memcpy( new_buffer + strlen(new_buffer), arch.ptr, len -
(arch.ptr - manifest) );