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

libvpx/source/libvpx/vp8/encoder/x86/quantize_mmx.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"
 
 ;int vp8_fast_quantize_b_impl_mmx(short *coeff_ptr, short *zbin_ptr,
 ;                           short *qcoeff_ptr,short *dequant_ptr,
 ;                           short *scan_mask, short *round_ptr,
 ;                           short *quant_ptr, short *dqcoeff_ptr);
-global sym(vp8_fast_quantize_b_impl_mmx)
+global sym(vp8_fast_quantize_b_impl_mmx) PRIVATE
 sym(vp8_fast_quantize_b_impl_mmx):
     push        rbp
     mov         rbp, rsp
     SHADOW_ARGS_TO_STACK 8
     push rsi
     push rdi
     ; end prolog
 
 
         mov             rsi,        arg(0) ;coeff_ptr
@@ skipping 248 matching lines @@
         ;    eob=15;
         ;}
         ;d->eob = eob+1;
 
     ; begin epilog
     pop rdi
     pop rsi
     UNSHADOW_ARGS
     pop         rbp
     ret