* thread_pthread.c (ruby_init_stack): Add STACK_GROW_DIR_DETECTION.
  This fixes a compilation failure while cross-compiling for Tensilica
  Xtensa Processor.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40498 b2dd03c8-39d4-4d8f-98ff-823fe69b080e