If you compile the kernel with -ffunction-sections, each function gets
put in a section .text.function_name.  This collides with our current use
of .text.init.  So here's a patch which converts x86 to use .init.text
instead.

I've tested it on x86 and it still frees 120k of ram, so it seems to work.
Other architectures will need to change their vmlinux.lds appropriately,
and may need other changes (arm, m68k seem to use .text.init verbatim).