Renamed NGX_THREADS to NGX_OLD_THREADS because of deprecation.

It's mostly dead code and the original idea of worker threads has been rejected.
diff --git a/src/core/nginx.c b/src/core/nginx.c
index c75ee4f..feb861a 100644
--- a/src/core/nginx.c
+++ b/src/core/nginx.c
@@ -139,7 +139,7 @@
       0,
       NULL },
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 
     { ngx_string("worker_threads"),
       NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
@@ -959,7 +959,7 @@
     ccf->user = (ngx_uid_t) NGX_CONF_UNSET_UINT;
     ccf->group = (ngx_gid_t) NGX_CONF_UNSET_UINT;
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
     ccf->worker_threads = NGX_CONF_UNSET;
     ccf->thread_stack_size = NGX_CONF_UNSET_SIZE;
 #endif
@@ -1000,7 +1000,7 @@
 
 #endif
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 
     ngx_conf_init_value(ccf->worker_threads, 0);
     ngx_threads_n = ccf->worker_threads;
diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index d6c0bda..896b775 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -943,7 +943,7 @@
         }
     }
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 
     /*
      * we have to clean the connection information before the closing
diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index 143cab7..207aea4 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -184,7 +184,7 @@
     unsigned            busy_count:2;
 #endif
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
     ngx_atomic_t        lock;
 #endif
 };
diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index d69783f..11e413f 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -26,7 +26,7 @@
 ngx_uint_t             ngx_test_config;
 ngx_uint_t             ngx_quiet_mode;
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 ngx_tls_key_t          ngx_core_tls_key;
 #endif
 
diff --git a/src/core/ngx_cycle.h b/src/core/ngx_cycle.h
index 21bf5ca..be90a72 100644
--- a/src/core/ngx_cycle.h
+++ b/src/core/ngx_cycle.h
@@ -103,7 +103,7 @@
      ngx_array_t              env;
      char                   **environment;
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
      ngx_int_t                worker_threads;
      size_t                   thread_stack_size;
 #endif
@@ -111,10 +111,14 @@
 } ngx_core_conf_t;
 
 
+#if (NGX_OLD_THREADS)
+
 typedef struct {
      ngx_pool_t              *pool;   /* pcre's malloc() pool */
 } ngx_core_tls_t;
 
+#endif
+
 
 #define ngx_is_init_cycle(cycle)  (cycle->conf_ctx == NULL)
 
@@ -136,7 +140,7 @@
 extern ngx_module_t           ngx_core_module;
 extern ngx_uint_t             ngx_test_config;
 extern ngx_uint_t             ngx_quiet_mode;
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 extern ngx_tls_key_t          ngx_core_tls_key;
 #endif
 
diff --git a/src/core/ngx_regex.c b/src/core/ngx_regex.c
index 30acca5..77c5947 100644
--- a/src/core/ngx_regex.c
+++ b/src/core/ngx_regex.c
@@ -80,7 +80,7 @@
 static ngx_inline void
 ngx_regex_malloc_init(ngx_pool_t *pool)
 {
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
     ngx_core_tls_t  *tls;
 
     if (ngx_threaded) {
@@ -98,7 +98,7 @@
 static ngx_inline void
 ngx_regex_malloc_done(void)
 {
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
     ngx_core_tls_t  *tls;
 
     if (ngx_threaded) {
@@ -253,7 +253,7 @@
 ngx_regex_malloc(size_t size)
 {
     ngx_pool_t      *pool;
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
     ngx_core_tls_t  *tls;
 
     if (ngx_threaded) {
diff --git a/src/core/ngx_spinlock.c b/src/core/ngx_spinlock.c
index 9c93afa..33477e2 100644
--- a/src/core/ngx_spinlock.c
+++ b/src/core/ngx_spinlock.c
@@ -42,7 +42,7 @@
 
 #else
 
-#if (NGX_THREADS)
+#if (NGX_OLD_THREADS)
 
 #error ngx_spinlock() or ngx_atomic_cmp_set() are not defined !