- Fixed a whole bunch of dependencies on defines between files, examples and tests

diff --git a/programs/test/selftest.c b/programs/test/selftest.c
index 4c43620..508d39d 100644
--- a/programs/test/selftest.c
+++ b/programs/test/selftest.c
@@ -117,12 +117,12 @@
         return( ret );
 #endif
 
-#if defined(POLARSSL_RSA_C)
+#if defined(POLARSSL_RSA_C) && defined(POLARSSL_BIGNUM_C)
     if( ( ret = rsa_self_test( v ) ) != 0 )
         return( ret );
 #endif
 
-#if defined(POLARSSL_X509_PARSE_C)
+#if defined(POLARSSL_X509_PARSE_C) && defined(POLARSSL_BIGNUM_C)
     if( ( ret = x509_self_test( v ) ) != 0 )
         return( ret );
 #endif