Avoid sizeof(void) in ASN.1 encoder

Avoid sizeof(void) in ASN.1 encoder

We were computing sizeof(void) when referencing atype_int_immediate
types in other types (primarily atype_tagged_thing).  gcc gives this a
pass but the Solaris compiler does not.  Use "int" as the dummy type
instead.  (The type is unimportant since int-immediates aren't used by
offset or sequence-of types.)

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@25658 dc483132-0cff-0310-8789-dd5450dbe970