On IA architecture, arithmetic and shifting operations set the flags
according to the computation result.

    subl rsi,0x1
    REX.W movq rbx,[rbx+0x17]
    cmpl rsi, 0                       <-- TO BE REDUCED
    jnz 0x3f54d2dcef0
==>
    REX.W movq rbx,[rbx+0x17]
    subl rsi,0x1
    jnz 0x3f54d2dcef0
&
    orl rdx,rbx
    cmpl rdx,0x0                      <-- TO BE REDUCED
    jnz 0x3f54d22b0f5
==>
    orl rdx,rbx
    jnz 0x3f54d22b0f5

Change-Id: If69c023712212ad7b9fa8b29f4b98274f7885e35
Reviewed-on: https://chromium-review.googlesource.com/1051445Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Kanghua Yu <kanghua.yu@intel.com>
Cr-Commit-Position: refs/heads/master@{#53118}