* The whilen and repeatn are now completely unified into whilerepeatn. This
allows the state tracker to change while nodes automatically into
repeat nodes.
* Resulttypepass improvements to the notn. 'not not a' is optimized away and
'not(a>b)' is optimized into 'a<=b'.
* Resulttypepass improvements to the whilerepeatn. 'while not a' is optimized
by removing the notn and later switchting the true and falselabels. The
same is done with 'repeat until not a'.
inlined from pexpr
* -an option that will write the secondpass nodes to the .s file, this
requires EXTDEBUG define to actually write the info
* fixed various internal errors and crashes due recent code changes
* register allocation is now handled by a class and is mostly processor
independent (+rgobj.pas and i386/rgcpu.pas)
* temp allocation is now handled by a class (+tgobj.pas, -i386\tgcpu.pas)
* some small improvements and fixes to the optimizer
* some register allocation fixes
* some fpuvaroffset fixes in the unary minus node
* push/popusedregisters is now called rg.save/restoreusedregisters and
(for i386) uses temps instead of push/pop's when using -Op3 (that code is
also better optimizable)
* fixed and optimized register saving/restoring for new/dispose nodes
* LOC_FPU locations now also require their "register" field to be set to
R_ST, not R_ST0 (the latter is used for LOC_CFPUREGISTER locations only)
- list field removed of the tnode class because it's not used currently
and can cause hard-to-find bugs
resulttype and first pass)
* made handling of read(ln)/write(ln) processor independent
* moved processor independent handling for str and reset/rewrite-typed
from firstpass to resulttype pass
* changed names of helpers in text.inc to be generic for use as
compilerprocs + added "iocheck" directive for most of them
* reading of ordinals is done by procedures instead of functions
because otherwise FPC_IOCHECK overwrote the result before it could
be stored elsewhere (range checking still works)
* compilerprocs can now be used in the system unit before they are
implemented
* added note to errore.msg that booleans can't be read using read/readln
