Argument1.AccessMode incorrectly set to READ for some instructions

[moritzkroll]

The AccessMode property is set to READ for the first argument for the following instructions, although the first argument is modified:

• btc / btr / bts
• cmpxchg8b/16b
• pmulhw/lw
• pmaddwd
• por
• pssl*
• psrl*
• psra*
• psub* (including psubs* and psubus*)
• punpck*
• pxor