Define PRIVATE and add it to all global symbols so we don't export assembly functions.

libvpx/source/libvpx/vpx_ports/emms.asm

 ;
 ;  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 ;
 ;  Use of this source code is governed by a BSD-style license
 ;  that can be found in the LICENSE file in the root of the source
 ;  tree. An additional intellectual property rights grant can be found
 ;  in the file PATENTS.  All contributing project authors may
 ;  be found in the AUTHORS file in the root of the source tree.
 ;
 
 
 %include "vpx_ports/x86_abi_support.asm"
 
 section .text
-    global sym(vpx_reset_mmx_state)
+    global sym(vpx_reset_mmx_state) PRIVATE
 sym(vpx_reset_mmx_state):
     emms
     ret
 
 
 %ifidn __OUTPUT_FORMAT__,x64
-global sym(vpx_winx64_fldcw)
+global sym(vpx_winx64_fldcw) PRIVATE
 sym(vpx_winx64_fldcw):
     sub   rsp, 8
     mov   [rsp], rcx ; win x64 specific
     fldcw [rsp]
     add   rsp, 8
     ret
 
 
-global sym(vpx_winx64_fstcw)
+global sym(vpx_winx64_fstcw) PRIVATE
 sym(vpx_winx64_fstcw):
     sub   rsp, 8
     fstcw [rsp]
     mov   rax, [rsp]
     add   rsp, 8
     ret
 %endif