Firefox24 build breaking because of non-existent strcasestr function

[Ibraheem Saleh <shadowhawk100%gmail.com@localhost>]

My Firefox24 build is breaking on Solaris 10 Sparc with gcc4.9.2 due
to the use of the strcasestr extension which doesn't exist on Solaris
10. Does anybody know a quick & valid fix for this?

It happens when compiling this file:
mozilla-esr24/widget/xpwidgets/GfxInfoX11.cpp

Here's the code block in question:
 whereToReadVersionNumbers = Mesa_in_version_string + strlen("Mesa");
        if (strcasestr(mVendor.get(), "nouveau"))
            mIsNouveau = true;
        if (strcasestr(mRenderer.get(), "intel")) // yes, intel is in
the renderer string
            mIsIntel = true;
        if (strcasestr(mRenderer.get(), "llvmpipe"))
            mIsLlvmpipe = true;
        if (strcasestr(mRenderer.get(), "software rasterizer"))
            mIsOldSwrast = true;
    } else if (strstr(mVendor.get(), "NVIDIA Corporation")) {

I appreciate the help :)