Strange wined3d crash

[Francois Gouget]

I am getting a strange wined3d crash during the d3d8:device test.

It's annoying because it only happens with the 64 bit build, and 
disappears if I add traces (+d3d or +d3d_shader), and even if I add a 
FIXME() just before the crash.

The crash happens in shader_glsl_ffp_vertex_lighting():
    shader_addline(buffer, "gl_FrontSecondaryColor = %s * specular;\n", specular);

According to the checks I've been able to do the specular pointer is 
still correct when this gets called.

Here's the backtrace:
http://pastebin.com/DKvXTVJn

Any idea what's up?
It almost feels like a compiler bug (gcc 4.9.2 (Debian 4.9.2-10) here).