1) didn't handle attempts to encode non-structs properly.
2) if there were multiple indirections involving allocation, didn't allocate the
intermediate cells.
tests added.

R=rsc
DELTA=82  (65 added, 5 deleted, 12 changed)
OCL=35582
CL=35582

  * generate different versions of binary operators
    for each size of int and float, so that proper
    truncating happens after each operation to
    simulate the various sized ops.
  * add slice expressions
  * publish World.CompileStmtList, CompileDeclList, CompileExpr
  * handle type-less expressions in CompileExpr

R=austin
DELTA=1459  (1327 added, 11 deleted, 121 changed)
OCL=34382
CL=35581

R=rsc
APPROVED=rsc
DELTA=25  (25 added, 0 deleted, 0 changed)
OCL=35566
CL=35574

R=rsc
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=35572
CL=35572

R=rsc
DELTA=7  (2 added, 0 deleted, 5 changed)
OCL=35569
CL=35569

R=rsc,r
APPROVED=rsc
DELTA=29  (2 added, 4 deleted, 23 changed)
OCL=35460
CL=35565

lock printf output to avoid interlacing debug prints.

R=r
DELTA=10  (7 added, 0 deleted, 3 changed)
OCL=35539
CL=35561

need to use exec to avoid seeing
shell output about the crash.

R=iant
DELTA=2  (1 added, 0 deleted, 1 changed)
OCL=35542
CL=35560

R=ken
OCL=35546
CL=35546

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=35526
CL=35540

so that the garbage collector doesn't free them.

R=ken
OCL=35538
CL=35538

R=rsc
DELTA=23  (22 added, 1 deleted, 0 changed)
OCL=35529
CL=35537

R=rsc
APPROVED=rsc
DELTA=637  (318 added, 318 deleted, 1 changed)
OCL=35534
CL=35536

cut the slowest tests  down from a few seconds
to under half a second.

R=r
DELTA=21  (6 added, 1 deleted, 14 changed)
OCL=35509
CL=35519

R=r
DELTA=23  (5 added, 0 deleted, 18 changed)
OCL=35510
CL=35518

go/test: passes 80% (274/340)

R=rsc
APPROVED=rsc
DELTA=61  (59 added, 0 deleted, 2 changed)
OCL=35506
CL=35517

R=iant
DELTA=125  (51 added, 53 deleted, 21 changed)
OCL=35508
CL=35511

fix bug198.

R=ken
OCL=35504
CL=35507

R=rsc
APPROVED=rsc
DELTA=27  (18 added, 0 deleted, 9 changed)
OCL=35503
CL=35505

R=rsc
DELTA=110  (98 added, 0 deleted, 12 changed)
OCL=35487
CL=35490

R=gri
OCL=35485
CL=35488

should let a 6g build and an 8g build be done in sequence
without stepping on each other.

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=35478
CL=35481

- honor line breaks in multi-line expressions
- do not add extra indentation to multi-line string lists
- don't put blanks around simple function calls and conversions
- do not modify `` strings
- added extra test cases

R=rsc
DELTA=398  (246 added, 51 deleted, 101 changed)
OCL=35453
CL=35465

R=rsc,r
APPROVED=r
DELTA=84  (77 added, 6 deleted, 1 changed)
OCL=35456
CL=35458

was discarding initialization work.

R=ken
OCL=35454
CL=35457

references during the parsing of :=.  the base
problem is that when reading

	a,b,c,d

the parser makes those refer to existing variables,
which might create a few stub top-level ones
for undefined names, but then if a := is the next
token, we need to undo those stubs.

this was causing problems in multifile packages
in which one file used a := variable named rpc
and the other imported a package named rpc.

R=ken
OCL=35446
CL=35446

R=r
DELTA=3  (2 added, 0 deleted, 1 changed)
OCL=35443
CL=35445

apply gofmt to rand reflect regexp rpc runtime sort strconv strings sync syscall testing time unicode unsafe utf8

R=gri
DELTA=1409  (79 added, 24 deleted, 1306 changed)
OCL=35415
CL=35437

- soft-tab separated columns can be discarded if empty and DiscardEmptyColumns is set
- hard-tab separated columns are never discarded

R=rsc
DELTA=63  (42 added, 7 deleted, 14 changed)
OCL=35421
CL=35435

R=r
DELTA=3214  (904 added, 2260 deleted, 50 changed)
OCL=35425
CL=35427

for lower-level clients:
	* expose p.Skip
	* expose p.Unmarshal
	* wildcard struct field "Any"
	* unmarshal into bool
	* unmarshal into xml.Name
	* unmarshal into pointer

R=r
DELTA=61  (50 added, 5 deleted, 6 changed)
OCL=35372
CL=35422

R=gri
DELTA=1359  (138 added, 32 deleted, 1189 changed)
OCL=35408
CL=35420

R=gri
DELTA=566  (4 added, 14 deleted, 548 changed)
OCL=35410
CL=35419

R=gri
DELTA=4023  (104 added, 27 deleted, 3892 changed)
OCL=35416
CL=35418

R=rsc
APPROVED=rsc
DELTA=58  (52 added, 3 deleted, 3 changed)
OCL=35417
CL=35417

- 64 bit OMINUS
- added bunch of missing arm syscalls

R=rsc
APPROVED=rsc
DELTA=203  (189 added, 3 deleted, 11 changed)
OCL=35412
CL=35414

TBR=gri
OCL=35411
CL=35411

- simplified some code

R=rsc
DELTA=19  (0 added, 0 deleted, 19 changed)
OCL=35405
CL=35407

R=gri
DELTA=456  (6 added, 3 deleted, 447 changed)
OCL=35398
CL=35406

got rid of regexps.
primary bug fix is that // inside /* */ do not get stripped anymore,
so that the text inside

/*
int a;
// int b;
int c;
*/

is

int a;
// int b;
int c;

before, the "int b;" line was being uncommented too.

R=gri
DELTA=65  (13 added, 42 deleted, 10 changed)
OCL=35334
CL=35404