Revert "Remove the global thread list."

This reverts commit b0e8c565a622b5519e03d4416b0b5b1a5f20d7f5.

Breaks swiftshader (http:/b/34883464).

Change-Id: I7b21193ba8a78f07d7ac65e41d0fe8516940a83b
diff --git a/libc/bionic/libc_init_common.cpp b/libc/bionic/libc_init_common.cpp
index 55a2e77..e5654c3 100644
--- a/libc/bionic/libc_init_common.cpp
+++ b/libc/bionic/libc_init_common.cpp
@@ -114,6 +114,10 @@
   __check_max_thread_id();
 #endif
 
+  // Get the main thread from TLS and add it to the thread list.
+  pthread_internal_t* main_thread = __get_thread();
+  __pthread_internal_add(main_thread);
+
   // Register atfork handlers to take and release the arc4random lock.
   pthread_atfork(arc4random_fork_handler, _thread_arc4_unlock, _thread_arc4_unlock);