* MIPS: rewrote 32-bit code generation methods, reducing code duplication.
+ Implemented overflow checking for unsigned 32-bit addition and subtraction.
* Use optimize_op_const instead of custom optimizations.
* Change AND/OR/XOR into ANDI/ORI/XORI if they use immediate operands, and use correct range for these immediate operands, must be 0..65535 unlike -32768..32767 for arithmetic operations.
* Don't treat AND/OR/XOR as macros, no longer necessary.
* Don't treat BEQ/BNE as macros either.


git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24445 3ad0048d-3df7-0310-abae-a5850022a9f2