* src/port.h,

* src/port.h,
* src/hc08/main.c,
* src/mcs51/main.c,
* src/ds390/main.c,
* src/z80/main.c,
* src/avr/main.c,
* src/pic/main.c,
* src/pic16/main.c,
* src/xa51/main.c: added hasExtBitOp & oclsExpense functions to ports
* src/SDCCicode.c: changed several IS_FARSPACE tests to isOclsExpensive
tests (which uses the port's oclsExpense function)
* src/SDCC.y,
* src/SDCCast.c,
* src/SDCCicode.c,
* src/hc08/gen.c,
* src/ds390/gen.c,
* src/mcs51/gen.c: added support for the SWAP iCode (RFE #834167)

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@2993 4a8a32a2-be11-0410-ad9d-d568d2c75423