mklib: clean up abi flags for x86 targets

The current code is duplicated in two places and relies on `uname` to
detect the flags.  This is no good for cross-compiling, and the current
logic uses -m64 for the x32 ABI which breaks things.

Unify the code in one place, avoid `uname` completely, and add support
for the new x32 ABI.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
1 file changed