[Sanitizer] Fix getpwnam test on ppc64le Fedora 21.

[foad]

Summary

On ppc64le Fedora 21, getpwnam_r("no-such-user", ...) returns ENOENT
instead of 0. Tolerate this in the test case.

[eugenis]

See this long discussion for the same problem on aarch64:
https://groups.google.com/d/msg/address-sanitizer/YzYRJEvVimw/qTbLWxGckXYJ

[foad]

In D9233#160897, @eugenis wrote:

See this long discussion for the same problem on aarch64:
https://groups.google.com/d/msg/address-sanitizer/YzYRJEvVimw/qTbLWxGckXYJ

Right. I see the same thing: even without the sanitizer, getpwnam_r returns ENOENT. And there's a comment from you in that discussion saying "Please change the assert to allow ENOENT in addition to 0." :-)

[eugenis]

Right :)
LGTM

test/sanitizer_common/TestCases/Linux/getpwnam_r_invalid_user.cc

 // Regression test for a crash in getpwnam_r and similar interceptors.
 // RUN: %clangxx -O0 -g %s -o %t && %run %t
 
 #include <assert.h>
+#include <errno.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 int main(void) {
   struct passwd pwd;
   struct passwd *pwdres;
   char buf[10000];
   int res = getpwnam_r("no-such-user", &pwd, buf, sizeof(buf), &pwdres);
-  assert(res == 0);
+  assert(res == 0 || res == ENOENT);
   assert(pwdres == 0);
   return 0;
 }