Fixes regression test result for anal.mips test4. But note differences with...

Fixes regression test for '-m' option for regression test 4 in anal.mips

However, something strange is happening: 
* Test 3 detects the end of function as the hard jump at address + 0x18 and a second function starting at 0x20
* Test 4 which uses the changed base address, detects the end of function as the `jr ra` at address + 0x20

TBH I am not really sure which should be considered the 'proper' end of function, I guess it depends on how you treat the equiva;ent of a 'goto' in code that is not necessarily generated by a C compiler; but I would have thought both analyses produce the same results as each other?