Added a test for the MIPS recip and rsqrt operations.
Marked as XFAIL the test for the inbuilt assembler understanding MIPS TLB
modification instructions.
Tweak a fragile test (it wants to check that the next line is not a nop, not that the next line is specifically an add).
Xfail two tests until I understand what they're testing.
Revert some code that allows the correct register to be used for PIC calls.
Add a test.