Investigate if/when BinaryOp.negated() should swap left/right for better matches

[zbanks]

Brought up by Maide on Discord.

A lot of if (y == x) statements output by mips2c need to be rewritten to if (x == y) to match.

This seems to be related to simplify_expression() and when (y == x) != 0 is re-written to y == x, but it needs more investigation to figure out how to make the matches better:

• Does it affect both integer & floats?
• Is it just equality, or also ordering comparisons? (Is there a certain set of instructions?)
• Can this be used to replace the 123 == x --> x == 123 reordering that's based on isinstance(..., Literal)?
• Is it consistent across both GCC & IDO?