nasm: add configure support

yasm has to be preferred as currently nasm produces marginally less
efficient code (longer opcodes). Filed for nasm as:

OTOH package should be built always the same, no matter which additional
packages are / are not present on the system. As the package should be
built with nasm (as yasm may not be available) we should not use yasm
even if it is possibly available.

nasm >= approx. 2.09 is required for the nasm compilation as the former
versions had a section alignment bug.

Provide nasm compatibility. No binary change by this patch with yasm on
{x86_64,i686}-fedora13-linux-gnu. Few longer opcodes with nasm on
{x86_64,i686}-fedora13-linux-gnu have been checked as safe.

Change-Id: Icb0fe39c64bbcc3bcd7972e392fd03f3273340df
2 files changed