test: Add a test for getopt

A few of these tests were inspired by those in glibc. The syntax for
invoking test_getopt is a bit funky, but it's necessary so that the CPP can
parse the arguments correctly.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
diff --git a/test/lib/Makefile b/test/lib/Makefile
index 15cd512..98a9abf 100644
--- a/test/lib/Makefile
+++ b/test/lib/Makefile
@@ -14,3 +14,4 @@
 obj-$(CONFIG_UT_LIB_ASN1) += asn1.o
 obj-$(CONFIG_UT_LIB_RSA) += rsa.o
 obj-$(CONFIG_AES) += test_aes.o
+obj-$(CONFIG_GETOPT) += getopt.o