add script to automate timing

R=rsc
DELTA=78  (68 added, 0 deleted, 10 changed)
OCL=32729
CL=32732

R=rsc
DELTA=682  (511 added, 171 deleted, 0 changed)
OCL=32725
CL=32727

split into typecheck + walk

R=ken
OCL=32726
CL=32726

R=ken
OCL=32716
CL=32720

start a log of progress

R=rsc
DELTA=222  (185 added, 17 deleted, 20 changed)
OCL=32701
CL=32718

R=rsc
DELTA=311  (311 added, 0 deleted, 0 changed)
OCL=32696
CL=32699

R=rsc
DELTA=40  (0 added, 0 deleted, 40 changed)
OCL=32694
CL=32698

R=rsc
DELTA=41  (41 added, 0 deleted, 0 changed)
OCL=32692
CL=32697

R=rsc
DELTA=28  (0 added, 20 deleted, 8 changed)
OCL=32676
CL=32684

R=rsc
DELTA=45  (28 added, 4 deleted, 13 changed)
OCL=32673
CL=32675

R=rsc
DELTA=19  (18 added, 0 deleted, 1 changed)
OCL=32656
CL=32670

typecheck.c is now responsible for all type checking
except for assignment and function argument "..."

R=ken
OCL=32661
CL=32667

- emit line tag id's in html mode
- support for general html tags
- better names for a few identifiers

godoc.go:
- emit links from exported names to source code
  (actual placement needs fine-tuning)

R=rsc
DELTA=108  (68 added, 4 deleted, 36 changed)
OCL=32639
CL=32654

- replace forward-declared types with complete
  declaration when it is found

R=rsc
DELTA=23  (15 added, 0 deleted, 8 changed)
OCL=32618
CL=32618

DELTA=5  (5 added, 0 deleted, 0 changed)
OCL=32484
CL=32617

- prepare for generation of HTML id tags and links
- do HTML-escaping in central print routine
- move tabwriter setup into printer
- fixed various TODOs

godoc:
- removed tabwriter setup, need for various HTML-escaping

R=rsc
DELTA=210  (107 added, 36 deleted, 67 changed)
OCL=32612
CL=32616

R=rsc
DELTA=100  (82 added, 4 deleted, 14 changed)
OCL=32609
CL=32615

types were supposed to be identical but only needed to be
compatible.  This gets rid of the Type.literal method.  I
renamed the Type.rep method to Type.lit because I believe it
corresponds to the term "literal" as used in the spec.

R=rsc
APPROVED=rsc
DELTA=228  (57 added, 35 deleted, 136 changed)
OCL=32606
CL=32608

the position where they were defined so I can produce good
error messages on redefinitions.

R=rsc
APPROVED=rsc
DELTA=204  (126 added, 13 deleted, 65 changed)
OCL=32599
CL=32605

R=rsc
DELTA=23  (23 added, 0 deleted, 0 changed)
OCL=32592
CL=32595

add commentary about findVar's invariant.

R=rsc
DELTA=6  (3 added, 0 deleted, 3 changed)
OCL=32583
CL=32594

R=rsc
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=32591
CL=32593

R=rsc
DELTA=73  (27 added, 25 deleted, 21 changed)
OCL=32587
CL=32587

R=ken
OCL=32581
CL=32581

R=ken
OCL=32576
CL=32580

- make token.Position.String more robust

TBR=rsc
DELTA=20  (10 added, 6 deleted, 4 changed)
OCL=32564
CL=32564

R=rsc
OCL=32563
CL=32563

handled by typecheck.

second switch is gone

move floating point minus into back end

R=ken
OCL=32558
CL=32558

R=rsc
DELTA=28  (19 added, 0 deleted, 9 changed)
OCL=32550
CL=32554

- more orthogonal functionality of filter functions for better re-use

go/doc/doc.go:
- simplified interface
- collect filenames of packages so that they can be shown

godoc:
- removed TODO, show list of package (linked) files used to create documentation

R=rsc
DELTA=130  (68 added, 24 deleted, 38 changed)
OCL=32549
CL=32552

R=gri
APPROVED=gri
DELTA=33  (20 added, 6 deleted, 7 changed)
OCL=32544
CL=32546

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=32540
CL=32545

started to move typechecking to another file.
can build entire tree still, but lots of work
is duplicated.  much to clean up.

R=ken
OCL=32536
CL=32543

let errchk exit 0 even if it has reported a BUG.
it echoed BUG and that's all that matters.

R=r
DELTA=143  (1 added, 89 deleted, 53 changed)
OCL=32533
CL=32542

Return checking is now done as a general flow check at the end
of function compilation, since break and goto complicated the
way I was doing return checking before.  Goto-over-declaration
checking is also done as a final flow check.

Temporary variables used for effect extraction are now
actually temporary.  Otherwise "op=", "++", and "--" appear as
declarations that cannot be jumped over.

R=rsc
APPROVED=rsc
DELTA=421  (344 added, 38 deleted, 39 changed)
OCL=32527
CL=32535

so that gdb shows full path in stack traces.

R=r
DELTA=4  (4 added, 0 deleted, 0 changed)
OCL=32522
CL=32528

R=ken
OCL=32521
CL=32521

roll back 32496

TBR=austin
OCL=32499
CL=32501

TBR=austin
OCL=32496
CL=32496

R=rsc
DELTA=154  (71 added, 6 deleted, 77 changed)
OCL=32483
CL=32492