memory callbacks missing on MIPS

[lacraig2]

MIPS is missing memory callbacks on more complicated instructions that involve helpers.

In particular, it is missing swr, swl, lwl, and lwr (and 64-bit equivalents).

https://github.com/panda-re/panda/blob/dev/target/mips/op_helper.c#L318-L358

Related: #1163, #1119