code review 5490053: runtime: make more build-friendly

src/pkg/runtime/mem_freebsd.c

 // Copyright 2010 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 "runtime.h"
-#include "arch.h"
-#include "defs.h"
-#include "os.h"
+#include "arch_GOARCH.h"
+#include "defs_GOOS_GOARCH.h"
+#include "os_GOOS.h"
 #include "malloc.h"
 
 void*
 runtime·SysAlloc(uintptr n)
 {
         void *v;
 
         mstats.sys += n;
         v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
         if(v < (void*)4096)
@@ skipping 51 matching lines @@
                 }
                 return;
         }
 
         p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
         if(p == (void*)-ENOMEM)
                 runtime·throw("runtime: out of memory");
         if(p != v)
                 runtime·throw("runtime: cannot map pages in arena address space");
 }