5g. fixes to 64 bit code gen. added (finally) function to do
shifts properly.

go/test: passes 83% (287/342)

R=rsc
APPROVED=rsc
DELTA=156  (50 added, 53 deleted, 53 changed)
OCL=35589
CL=35616

turn off testdclstack and "not used" errors
when there are syntax errors.

BUG=2181825
R=ken
OCL=35606
CL=35608

  * in 6l, -K already meant check for stack underflow.
    add -KK to mean double-check stack overflows
    even in nosplit functions.

  * comment out print locks; they deadlock too easily
     but are still useful to put back for special occasions.

  * let runcgo assembly switch to scheduler stack
    without involving scheduler directly.  because runcgo
    gets called from matchmg, it is too hard to keep it
    from being called on other stacks.

R=r
DELTA=94  (65 added, 18 deleted, 11 changed)
OCL=35591
CL=35604

node printing fixes.
silence incorrect redeclaration error.

R=ken
OCL=35602
CL=35602

add bytes.LastIndex.
add strings.Reader.

R=r
DELTA=59  (56 added, 0 deleted, 3 changed)
OCL=35585
CL=35601

good enough to parse some html.

in reader, add "comment" tag to collect
comment text.

do not allocate during Unmarshal unless pointer is nil.

R=r
DELTA=441  (416 added, 1 deleted, 24 changed)
OCL=35586
CL=35594

leave that for Btoi with base == 0.

R=r
DELTA=146  (101 added, 29 deleted, 16 changed)
OCL=35584
CL=35593

TBR=r
OCL=35592
CL=35592

reflect is broken so fmt doesn't work.

go/test: passes 83% (285/342)

R=rsc
APPROVED=rsc
DELTA=415  (240 added, 29 deleted, 146 changed)
OCL=35576
CL=35588

R=r,rsc
APPROVED=r
DELTA=122  (102 added, 0 deleted, 20 changed)
OCL=35573
CL=35587

R=rsc
DELTA=11  (3 added, 5 deleted, 3 changed)
OCL=35583
CL=35583

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