For the following code, we need to check 'type_attr.form'.
type_attr = DIE.attributes["DW_AT_type"]
base_type_die = dwarfinfo.get_DIE_from_refaddr(xxx)
When type_attr.form==DW_FORM_ref_addr, 'type_attr.value' means
global reference (across compilation units).
When type_attr.form==DW_FORM_ref4, 'type_attr.value' means
local reference (within the same compilation unit).
Signed-off-by: yukangzhi <yukangzhi@xiaomi.com>