init function context.
also moved composit literal
code from walk.c to sinit.c

R=rsc
OCL=34503
CL=34503

R=ken
OCL=34500
CL=34500

R=r
DELTA=9  (7 added, 0 deleted, 2 changed)
OCL=34499
CL=34499

R=rsc
DELTA=28  (7 added, 16 deleted, 5 changed)
OCL=34487
CL=34487

R=ken
OCL=34478
CL=34480

x == nil
x.go:5: cannot use nil as bool

c := x.(type);
x.go:88: use of .(type) outside type switch

R=ken
OCL=34476
CL=34476

universe block names.

BUG=2097244
R=ken
OCL=34295
CL=34473

R=ken
OCL=34471
CL=34471

R=ken
OCL=34465
CL=34470

R=rsc
DELTA=22  (19 added, 0 deleted, 3 changed)
OCL=34463
CL=34463

R=rsc
OCL=34462
CL=34462

- fixed a couple of broken links
- changed some explicit section references into implicit ones

R=r
DELTA=27  (0 added, 2 deleted, 25 changed)
OCL=34461
CL=34461

R=r
DELTA=24  (15 added, 0 deleted, 9 changed)
OCL=34447
CL=34458

- adjusted a test to check claim

R=rsc
DELTA=3  (2 added, 0 deleted, 1 changed)
OCL=34454
CL=34456

R=rsc
OCL=34453
CL=34455

they can get the official alignment out of there
instead of guessing.

R=ken
OCL=34450
CL=34450

add comments showing Go syntax for each token.
move doc comments below hidden begin constants

R=gri
DELTA=66  (3 added, 3 deleted, 60 changed)
OCL=34334
CL=34445

R=rsc
OCL=34434
CL=34434

almost done

R=rsc
OCL=34422
CL=34422

plateau - more to come

R=rsc
OCL=34413
CL=34413

R=rsc
APPROVED=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=34404
CL=34406

tweak test/literal.go to give more information.

R=austin
DELTA=45  (43 added, 0 deleted, 2 changed)
OCL=34381
CL=34398

successful.

R=rsc
APPROVED=rsc
DELTA=43  (31 added, 0 deleted, 12 changed)
OCL=34375
CL=34397

R=rsc
APPROVED=rsc
DELTA=314  (132 added, 2 deleted, 180 changed)
OCL=34376
CL=34396

R=rsc
APPROVED=rsc
DELTA=328  (112 added, 110 deleted, 106 changed)
OCL=34356
CL=34356

R=austin
DELTA=21  (5 added, 10 deleted, 6 changed)
OCL=34355
CL=34355

implementations can abort.  Make genConstant get values lazily
since we need the Thread now.

R=rsc
APPROVED=rsc
DELTA=299  (8 added, 19 deleted, 272 changed)
OCL=34353
CL=34353

R=austin
DELTA=34  (34 added, 0 deleted, 0 changed)
OCL=34280
CL=34352

including breakpoints and Go thread create/exit.

R=rsc
APPROVED=rsc
DELTA=751  (729 added, 6 deleted, 16 changed)
OCL=34345
CL=34351

arithmetic unary operators + - ^

R=r
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=34338
CL=34350

start on Decl, but not working yet

R=austin
DELTA=762  (201 added, 205 deleted, 356 changed)
OCL=34335
CL=34349

R=ken
OCL=34348
CL=34348

R=austin
DELTA=140  (128 added, 0 deleted, 12 changed)
OCL=34344
CL=34347

R=austin
DELTA=23  (23 added, 0 deleted, 0 changed)
OCL=34340
CL=34346

R=r
DELTA=13  (5 added, 6 deleted, 2 changed)
OCL=34337
CL=34343

R=ken
OCL=34339
CL=34341

R=r
DELTA=42  (21 added, 20 deleted, 1 changed)
OCL=34328
CL=34333

R=rsc
DELTA=20  (20 added, 0 deleted, 0 changed)
OCL=34330
CL=34332

main changes:
	gccgo is much slower on  binary-tree and fannkuch
	6g seems to struggle with alignment of loops in nbody (dignosis uncertain)
	6g is a little faster at regexps and concurrency

R=rsc
DELTA=93  (93 added, 0 deleted, 0 changed)
OCL=34320
CL=34322

R=austin
DELTA=26  (0 added, 26 deleted, 0 changed)
OCL=34294
CL=34317