[krbdev.mit.edu #8605] OS X SIP breaks some tests in "make check"

[Greg Hudson via RT]

By default, OS X 10.11 enables a hardening feature called System 
Integrity Protection.  One of the consequences of SIP is that each 
/bin/sh process unsets the DYLD_LIBRARY_PATH variable.

We have a few tests in make check which are implemented as shell 
scripts, including (but probably not limited to) lib/krb5/krb/transit-
tests and lib/krb5/krb/walktree-tests.  These test scripts will not 
correctly find libraries in the build tree with SIP turned on.  A 
workaround is to run "make install" before "make check", but we should 
try to work around the SIP protections, either by setting 
DYLD_LIBRARY_PATH from within testing shell scripts or by avoiding the 
use of shell scripts in make check.