* MIPS small improvements:
  * TCGMIPS.a_load_reg_reg: generate CPU instructions instead of macros
  * TCGMIPS.a_cmp_const_reg_label: load constant using a_load_const_reg instead of LI macro (it may also end up with LI, but tries to optimize when possible).
  - removed unused variables.


git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24418 3ad0048d-3df7-0310-abae-a5850022a9f2