code review 109050043: all: remove 'extern register M *m' from runtime

src/pkg/runtime/cgo/gcc_darwin_amd64.c

 // Copyright 2009 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include <string.h> /* for strerror */
 #include <pthread.h>
 #include <signal.h>
 #include "libcgo.h"
 
 static void* threadentry(void*);
 static pthread_key_t k1;
 
 #define magic1 (0x23581321345589ULL)
 
 static void
 inittls(void)
 {
         uint64 x;
         pthread_key_t tofree[128], k;
         int i, ntofree;
 
         /*
          * Same logic, code as darwin_386.c:/inittls, except that words
          * are 8 bytes long now, and the thread-local storage starts
-         * at 0x60 on Leopard / Snow Leopard. So the offsets are
-         * 0x60+8*0x108 = 0x8a0 and 0x60+8*0x109 = 0x8a8.
+         * at 0x60 on Leopard / Snow Leopard. So the offset is
+         * 0x60+8*0x108 = 0x8a0.
          *
-         * The linker and runtime hard-code these constant offsets
-         * from %gs where we expect to find m and g.
-         * Known to ../../../cmd/6l/obj.c:/8a0
+         * The linker and runtime hard-code this constant offset
+         * from %gs where we expect to find g.
+         * Known to ../../../liblink/sym.c:/8a0
          * and to ../sys_darwin_amd64.s:/8a0
          *
          * As disgusting as on the 386; same justification.
          */
         ntofree = 0;
         for(;;) {
                 if(pthread_key_create(&k, nil) < 0) {
                         fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
                         abort();
                 }
@@ skipping 76 matching lines @@
          * _cgo_sys_thread_start set stackguard to stack size;
          * change to actual guard pointer.
          */
         ts.g->stackguard = (uintptr)&ts - ts.g->stackguard + 4096;
 
         pthread_setspecific(k1, (void*)ts.g);
 
         crosscall_amd64(ts.fn);
         return nil;
 }