Allocate thread local buffers in __init_tls.

Thread local buffers were using pthread_setspecific for storage with
lazy initialization. pthread_setspecific shares TLS slots between the
linker and libc.so, so thread local buffers being initialized in a
different order between libc.so and the linker meant that bad things
would happen (manifesting as snprintf not working because the
locale was mangled)

Bug: http://b/20464031
Test: /data/nativetest64/bionic-unit-tests/bionic-unit-tests
      everything passes
Test: /data/nativetest/bionic-unit-tests/bionic-unit-tests
      thread_local tests are failing both before and after (KUSER_HELPERS?)
Test: /data/nativetest64/bionic-unit-tests-static/bionic-unit-tests-static
      no additional failures
Change-Id: I9f445a77c6e86979f3fa49c4a5feecf6ec2b0c3f
diff --git a/libc/bionic/strsignal.cpp b/libc/bionic/strsignal.cpp
index c389ddd..81a8f95 100644
--- a/libc/bionic/strsignal.cpp
+++ b/libc/bionic/strsignal.cpp
@@ -27,13 +27,12 @@
  */
 
 #include <string.h>
-#include "private/ThreadLocalBuffer.h"
+
+#include "bionic/pthread_internal.h"
 
 extern "C" const char* __strsignal_lookup(int);
 extern "C" const char* __strsignal(int, char*, size_t);
 
-static ThreadLocalBuffer<char, NL_TEXTMAX> g_strsignal_tls_buffer;
-
 char* strsignal(int signal_number) {
   // Just return the original constant in the easy cases.
   char* result = const_cast<char*>(__strsignal_lookup(signal_number));
@@ -41,6 +40,6 @@
     return result;
   }
 
-  return const_cast<char*>(__strsignal(signal_number, g_strsignal_tls_buffer.get(),
-                                       g_strsignal_tls_buffer.size()));
+  bionic_tls& tls = __get_bionic_tls();
+  return const_cast<char*>(__strsignal(signal_number, tls.strsignal_buf, sizeof(tls.strsignal_buf)));
 }