Incorrect translation of OPCODE_UDIV and OPCODE_SWAPC

[TiemoJung]

H,

at least for the GLSL output the translation of OPCODE_UDIV and OPCODE_SWAPC can result in incorrect GLSL code.

As udiv calculates the division and reminder in one step and may overwrite both input registers, the currently emitted GLSL code is incorrect. This is also the same with OPCODE_SWAPC.