i965: Use __attribute__((flatten)) on fast tiled teximage code.

i965: Use __attribute__((flatten)) on fast tiled teximage code.

The fast tiled texture upload code does not compile with GCC 4.8's -Og
optimization flag.

memcpy() has the always_inline attribute set.  This poses a problem,
since {x,y}tile_copy_faster calls it indirectly via {x,y}tile_copy,
and {x,y}tile_copy normally aren't inlined at -Og.

Using __attribute__((flatten)) tells GCC to inline every function call
inside the function, which I believe was the author's intent.

Fix suggested by Alexander Monakov.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Cc: mesa-stable@lists.freedesktop.org