firefox and palemoon fix build with Glibc lesser than 2.12 version

# HG changeset patch
# User Andrew Paprocki <[email protected]>
# Date 1429932392 14400
#      Fri Apr 24 23:26:32 2015 -0400
# Node ID df67e9784e4089fe57653aa766c893ac60b6bdd4
# Parent  ccd270cfe90bd2ee68a3865fcf1c06175f6f9f00
Bug 1107944 - Support setting thread name on systems without glibc-2.12. r=jorendorff

diff --git a/js/src/vm/PosixNSPR.cpp b/js/src/vm/PosixNSPR.cpp
--- a/js/src/threading/posix/Thread.cpp
+++ b/js/src/threading/posix/Thread.cpp
@@ -159,8 +159,14 @@
   rv = 0;
 #elif defined(__NetBSD__)
   rv = pthread_setname_np(pthread_self(), "%s", (void*)name);
+#elif defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 12)
+  rv = pthread_setname_np(pthread_self(), name);
+#elif defined(__linux) && defined(PR_SET_NAME)
+  // PR_SET_NAME was added in Linux 2.6.9 and is the fallback when the
+  // newer pthread_setname_np() added in glibc-2.12 is not available.
+  rv = prctl(PR_SET_NAME, (unsigned long)(uintptr_t)name, 0, 0, 0);
 #else
-  rv = pthread_setname_np(pthread_self(), name);
+  rv = -1;
 #endif
   MOZ_RELEASE_ASSERT(!rv);
 }