RT3230: Better test for C identifier

objects.pl only looked for a space to see if the name could be
used as a C identifier.  Improve the test to match the real C
rules.

Signed-off-by: Rich Salz <rsalz@akamai.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 591b7aef)