libobjc: Add local macros to support encode generation [P109913].
r14-976-g9907413a3a6aa3 alters code to use the preferred _P-style
macros rather than direct comparisons of (for example) tree codes.
In the context of libobjc this does not work, since we do not include
the relevant headers; the encoding implementation contains a local
emulation of the target type layouts.
The fix here provides relevant macros local to the use.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
PR libobjc/109913
libobjc/ChangeLog:
* encoding.c (RECORD_OR_UNION_TYPE_P, VECTOR_TYPE_P): New.
Co-authored-by: Andrew Pinski <apinski@marvell.com>