Support VOP1/2 being used as VOP3a/b

[balidani]

Currently this is not supported. It might be difficult to tell which format to use, it can't be decided solely based on the number of operands passed.

For example:

v_add_i32 v8, vcc, v3, v7 ; 4A100F03

This instruction specifies "vcc" as the destination for the carry-out, which a VOP2 instruction wouldn't be allowed to do. Since "vcc" is the default though, this probably gets optimized and the output is in VOP2 format.