Add PRIVATE flags to global symbols

simd/jcgryext-sse2.asm

 ;
 ; jcgryext.asm - grayscale colorspace conversion (SSE2)
 ;
 ; x86 SIMD extension for IJG JPEG library
 ; Copyright (C) 1999-2006, MIYASAKA Masaru.
 ; Copyright (C) 2011, D. R. Commander.
 ; For conditions of distribution and use, see copyright notice in jsimdext.inc
 ;
 ; This file should be assembled with NASM (Netwide Assembler),
 ; can *not* be assembled with Microsoft's MASM or any compatible
@@ skipping 21 matching lines @@
 %define output_row(b)   (b)+20          ; JDIMENSION output_row
 %define num_rows(b)     (b)+24          ; int num_rows
 
 %define original_ebp    ebp+0
 %define wk(i)           ebp-(WK_NUM-(i))*SIZEOF_XMMWORD ; xmmword wk[WK_NUM]
 %define WK_NUM          2
 %define gotptr          wk(0)-SIZEOF_POINTER    ; void * gotptr
 
         align   16
 
-        global  EXTN(jsimd_rgb_gray_convert_sse2)
+        global  EXTN(jsimd_rgb_gray_convert_sse2) PRIVATE
 
 EXTN(jsimd_rgb_gray_convert_sse2):
         push    ebp
         mov     eax,esp                         ; eax = original ebp
         sub     esp, byte 4
         and     esp, byte (-SIZEOF_XMMWORD)     ; align to 128 bits
         mov     [esp],eax
         mov     ebp,esp                         ; ebp = aligned ebp
         lea     esp, [wk(0)]
         pushpic eax             ; make a room for GOT address
@@ skipping 321 matching lines @@
 ;       pop     ecx             ; need not be preserved
         pop     ebx
         mov     esp,ebp         ; esp <- aligned ebp
         pop     esp             ; esp <- original ebp
         pop     ebp
         ret
 
 ; For some reason, the OS X linker does not honor the request to align the
 ; segment unless we do this.
         align   16