* src/pic16/device.c (checkAddSym): NEW, adds a symbol to set while

* src/pic16/device.c (checkAddSym): NEW, adds a symbol to set while
checking if symbol is already in set,
* src/pic16/device.h: prototype for checkAddSym,
* src/pic16/gen.c: (_G): added entry interruptvector,
* (assignResultValue): removed some commented out lines,
* (genFunction): check for ISR via sym->type, absolute section for
interrupt code is created via a new pBlock, the goto instruction is
placed now correctly at the interrupt vector position, changed all
references from ivec to _G.interruptvector,
* WREG,STATUS,BSR are not saved in stack upon an entry to interrupt
is the interrupt is a high priority one, same for return from ISR,
* src/pic16/glue.c: changed all calls of addSetHead for publics and
externs to calls of checkAddSym,
* src/pic16/pcode.c (pic16_pBlockConvert2*): emit warning when
pic16_pcode_verbose flag is set,
* src/pic16/pcode.h: extern to pic16_pcode_verbose,
* src/pic16/pcoderegs.c: message about how many registers are saved
will only be emitted if pic16_pcode_verbose flag is set,

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@3241 4a8a32a2-be11-0410-ad9d-d568d2c75423