remove `NON_SCALAR_THREAD_ID` support

`NON_SCALAR_THREAD_ID` shows `pthread_t` is non-scalar (non-pointer)
and only s390x is known platform. However, the supporting code is
very complex and it is only used for deubg print information.

So this patch removes the support of `NON_SCALAR_THREAD_ID`
and make the code simple.

1 files changed, 0 insertions, 4 deletions

diff --git a/vm.c b/vm.c
index 3b478d848a..76041b0b91 100644
--- a/vm.c
+++ b/vm.c
@@ -3275,10 +3275,6 @@ th_init(rb_thread_t *th, VALUE self, rb_vm_t *vm)
     th->top_self = vm->top_self; // 0 while self == 0
     th->value = Qundef;
 
-#if  defined(NON_SCALAR_THREAD_ID) && !defined(__wasm__) && !defined(__EMSCRIPTEN__)
-    th->nt->thread_id_string[0] = '\0';
-#endif
-
     th->ec->errinfo = Qnil;
     th->ec->root_svar = Qfalse;
     th->ec->local_storage_recursive_hash = Qnil;