Kernel/LibC/DynamicLoader: Implement thread local storage

For some reason this does not work on 32 bit version, so it is disabled
on that platform. I'll have to look into it later to find the bug :)

userspace/libraries/LibC/errno.cpp

@@ -1,6 +1,10 @@
 #include <errno.h>
 
+#if __disable_thread_local_storage
 static int s_errno = 0;
+#else
+static thread_local int s_errno = 0;
+#endif
 
 int* __errno_location()
 {