TCG x86/x86-64: use move with zero-extend for loads/stores

TCG x86/x86-64: use move with zero-extend for loads/stores

Starting with version 4.3, gcc returns the result of a function in
rax/eax/ax/al instead of rax/eax, depending of the return type. As
a consequence we should use a zero extend moe in TCG loads/stores.

See http://gcc.gnu.org/ml/gcc/2008-01/msg00052.html for more details.

A big thanks to malc who founds the problem and wrote the x86 patch.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6011 c046a42c-6fe2-441c-8c8c-71466251a162