Rename TARGET_OS_* to HOST_OS_*.

runtime/vm/snapshot.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 854 matching lines @@
       ASSERT(Utils::IsAligned(end, sizeof(uint64_t)));
 
       for (uword* cursor = reinterpret_cast<uword*>(entry);
            cursor < reinterpret_cast<uword*>(end); cursor++) {
         WriteWordLiteralText(*cursor);
       }
     }
   }
 
 
-#if defined(TARGET_OS_LINUX)
+#if defined(HOST_OS_LINUX)
   assembly_stream_.Print(".section .rodata\n");
-#elif defined(TARGET_OS_MACOS)
+#elif defined(HOST_OS_MACOS)
   assembly_stream_.Print(".const\n");
 #else
   // Unsupported platform.
   UNREACHABLE();
 #endif
 
   const char* data_symbol =
       vm ? "_kDartVmSnapshotData" : "_kDartIsolateSnapshotData";
   assembly_stream_.Print(".globl %s\n", data_symbol);
   assembly_stream_.Print(".balign %" Pd ", 0\n",
@@ skipping 1051 matching lines @@
       *buffer_len_ = BytesWritten();
     }
   } else {
     FreeBuffer();
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart