target-i386: xsave: Helper function to calculate xsave area size Move the xsave area size calculation from cpu_x86_cpuid() inside its own function. While doing it, change it to use the XSAVE area struct sizes for the initial size, instead of the magic 0x240 number. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>