This patch affects only the vex version of the instructions, preparing for the evex form.
DynamoRIO does not break down exactly the memory locations that are read by vunpck* instructions in its operand size type. The OPSZ_8_of_16_vex32 does not exactly apply to the vex version as actually 16 bytes are read. This patch adds a new size OPSZ_half_16_vex32. The new size fixes the operand's memory size as well as fixes the type of src1 for instructions above.
Issue: #1312