Add missing change from 'Rewrite the JDIMENSION argument management for x86 64-bit assembly'

simd/jcsamss2-64.asm

 ;
 ; jcsamss2-64.asm - downsampling (64-bit SSE2)
 ;
 ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
 ; Copyright 2009 D. R. Commander
 ;
 ; Based on
 ; x86 SIMD extension for IJG JPEG library
 ; Copyright (C) 1999-2006, MIYASAKA Masaru.
 ; For conditions of distribution and use, see copyright notice in jsimdext.inc
@@ skipping 179 matching lines @@
 EXTN(jsimd_h2v2_downsample_sse2):
         push    rbp
         mov     rax,rsp
         mov     rbp,rsp
         collect_args
 
         mov     ecx, r13d
         shl     rcx,3                   ; imul rcx,DCTSIZE (rcx = output_cols)
         jz      near .return
 
-        mov     rdx, r10
+        mov     edx, r10d
 
         ; -- expand_right_edge
 
         push    rcx
         shl     rcx,1                           ; output_cols * 2
         sub     rcx,rdx
         jle     short .expand_end
 
         mov     rax, r11
         test    rax,rax
@@ skipping 110 matching lines @@
         jg      near .rowloop
 
 .return:
         uncollect_args
         pop     rbp
         ret
 
 ; For some reason, the OS X linker does not honor the request to align the
 ; segment unless we do this.
         align   16