Update to NSS 3.15.5 and NSPR 4.10.3.

nspr/pr/src/pthreads/ptio.c

Index: nspr/pr/src/pthreads/ptio.c
===================================================================
--- nspr/pr/src/pthreads/ptio.c	(revision 251855)
+++ nspr/pr/src/pthreads/ptio.c	(working copy)
@@ -3400,8 +3400,6 @@
 extern PRBool _pr_ipv6_is_present(void);
 PR_IMPLEMENT(PRBool) _pr_test_ipv6_socket()
 {
-PRInt32 osfd;
-
 #if defined(DARWIN)
     /*
      * Disable IPv6 if Darwin version is less than 7.0.0 (OS X 10.3).  IPv6 on
@@ -3414,18 +3412,24 @@
     }
 #endif
 
+#if defined(LINUX)
+    /* If /proc/net/if_inet6 exists, the Linux kernel supports IPv6. */
+    int rv = access("/proc/net/if_inet6", F_OK);
+    return (rv == 0);
+#else
     /*
      * HP-UX only: HP-UX IPv6 Porting Guide (dated February 2001)
      * suggests that we call open("/dev/ip6", O_RDWR) to determine
      * whether IPv6 APIs and the IPv6 stack are on the system.
      * Our portable test below seems to work fine, so I am using it.
      */
-    osfd = socket(AF_INET6, SOCK_STREAM, 0);
+    PRInt32 osfd = socket(AF_INET6, SOCK_STREAM, 0);
     if (osfd != -1) {
         close(osfd);
         return PR_TRUE;
     }
     return PR_FALSE;
+#endif
 }
 #endif	/* _PR_INET6_PROBE */
 #endif