qdev: Let qdev_prop_parse() pass through Error

Move error reporting to callers.

Signed-off-by: Andreas Färber <afaerber@suse.de>
qdev: Introduce qdev_prop_set_custom_globals()

Reuse it in qdev_prop_set_globals().

Signed-off-by: Andreas Färber <afaerber@suse.de>
target-i386: Emulate X86CPU subclasses for global properties

After initializing the object from its x86_def_t and before setting any
additional -cpu arguments, set any global properties for the designated
subclass <name>-{i386,x86_64}-cpu.

Signed-off-by: Andreas Färber <afaerber@suse.de>
target-i386: Change CPUID model of 486 to 8

This changes the model number of 486 to 8 (DX4) which matches the
feature set presented, and actually has the CPUID instruction.

This adds a compatibility property, to keep model=0 on pc-*-1.4 and older.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
[AF: Add compat_props entry]
Signed-off-by: Andreas Färber <afaerber@suse.de>