the interpreter and update code to use ast.BasicDecl and
multi-type switch.  There are still a lot of "switch _ :=
x.(type)" that should make use of the new type switch syntax,
but those will be a different CL.

R=rsc
APPROVED=rsc
DELTA=58  (16 added, 23 deleted, 19 changed)
OCL=34853
CL=34963

hasn't been ported to the new sym package yet)

R=rsc
APPROVED=rsc
DELTA=9  (0 added, 1 deleted, 8 changed)
OCL=34851
CL=34962

	and report node type in error

R=gri
DELTA=4  (3 added, 0 deleted, 1 changed)
OCL=34949
CL=34955

let the browser use the font the user has set up
as the default fixed-width font, instead of forcing Courier.

also set the size to 100%, which means 100% of the
font size in the surrounding text.  this looks a little
better in the main body but much better when the
code is in a heading (like Package unsafe).

R=r
DELTA=4  (1 added, 0 deleted, 3 changed)
OCL=34947
CL=34947

existing interface still works.

R=rsc
DELTA=50  (32 added, 2 deleted, 16 changed)
OCL=34930
CL=34932

R=rsc
DELTA=161  (57 added, 56 deleted, 48 changed)
OCL=34926
CL=34929

special all-nacl.bash and test/run-nacl that
run just the tests known to work under nacl.
the rest requires closures.

fix another bug or two in syscall.

R=r
DELTA=420  (410 added, 8 deleted, 2 changed)
OCL=34882
CL=34907

  * change ldt0setup to set GS itself; nacl won't let us do it.
  * change breakpoint to INT $3 so 8l can translate to HLT for nacl.
  * panic if closure is needed on nacl.
  * do not try to access symbol table on nacl.
  * mmap in 64kB chunks.

nacl support:
  * system calls, threading, locks.

R=r
DELTA=365  (357 added, 5 deleted, 3 changed)
OCL=34880
CL=34906

but too slow across the board.

R=rsc
DELTA=315  (50 added, 219 deleted, 46 changed)
OCL=34868
CL=34902

R=rsc
DELTA=57  (57 added, 0 deleted, 0 changed)
OCL=34896
CL=34901

go/test: passes 64% (215/337) tests

metric updated, had total number of tests wrong. number of
failing tests is down from 129 to 122.

R=rsc
APPROVED=rsc
DELTA=228  (12 added, 5 deleted, 211 changed)
OCL=34897
CL=34899

R=r
DELTA=18  (0 added, 0 deleted, 18 changed)
OCL=34894
CL=34894

R=r
DELTA=515  (515 added, 0 deleted, 0 changed)
OCL=34881
CL=34891

similar tweaks to make debug/proc, net, os build.

R=r
DELTA=861  (855 added, 4 deleted, 2 changed)
OCL=34877
CL=34890

deciding what the host process support is.
this makes a cross-compiling (e.g., GOOS=nacl) build
still generate valid host debugger binaries.

R=r
DELTA=5  (0 added, 0 deleted, 5 changed)
OCL=34878
CL=34889

	add jmp to constant pc.
	generate HLT for INT $3
	do not insert NOPs between REP/REPN and subsequent instruction.
	allow very long time for convergence.

R=ken
OCL=34879
CL=34879

R=r
DELTA=305  (305 added, 0 deleted, 0 changed)
OCL=34848
CL=34875

R=rsc
OCL=34871
CL=34871

R=r
DELTA=89  (82 added, 5 deleted, 2 changed)
OCL=34870
CL=34870

can JMP or CALL indirect through a register R
provided the preceding instruction is AND $~31, R.

R=ken
OCL=34863
CL=34867

required for nacl and may be nicer for ffi,
because %gs is the standard register for thread-local storage.

R=ken
OCL=34861
CL=34866

R=ken
OCL=34859
CL=34865

R=r
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=34860
CL=34864

delete strings.Buffer
add a test for a bug not caught before (mustn't install zero-length blocks)

R=rsc
DELTA=987  (289 added, 587 deleted, 111 changed)
OCL=34850
CL=34850

make strings.Buffer handle strings and bytes with comparable efficiency.
if ok, next step will be to move this code to bytes.Buffer and terminate
strings.Buffer's short happy life.

R=rsc
DELTA=292  (212 added, 0 deleted, 80 changed)
OCL=34837
CL=34849

R=ken
OCL=34845
CL=34845

libpng.org.

R=rsc
APPROVED=r
DELTA=1176  (1175 added, 1 deleted, 0 changed)
OCL=34727
CL=34838

- removed some unused code

R=rsc
DELTA=103  (84 added, 15 deleted, 4 changed)
OCL=34816
CL=34829

R=ken
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=34828
CL=34828

R=kaib
OCL=34823
CL=34823

R=rsc
APPROVED=rsc
DELTA=300  (297 added, 0 deleted, 3 changed)
OCL=34813
CL=34821

R=rsc
APPROVED=rsc
DELTA=7  (3 added, 0 deleted, 4 changed)
OCL=34661
CL=34820

  - ELF header bits and addresses
  - do not let instructions span 32-byte boundary
  - align CALLs so return is to 32-byte boundary
  - align indirect jump targets to 32-byte boundary
    (only possible indirect jumps are function entries)

still to do:
  - replace indirect jump, indirect call, and ret with
    nacl-approved instruction sequences
  - switch to GS segment for m-local storage

R=ken
OCL=34818
CL=34818

having one copy will cut nacl changes in half.

R=ken
OCL=34815
CL=34815

params. a number of fixes to assembly routines that assumed R0
had the first arg. one stack offset fix, arm pushes the link
register on stack top.

go/test: passes 65% (235/364) tests

R=rsc
APPROVED=rsc
DELTA=20  (11 added, 0 deleted, 9 changed)
OCL=34809
CL=34812

TBR=r
OCL=34803
CL=34803

R=rsc
APPROVED=rsc
DELTA=115  (93 added, 14 deleted, 8 changed)
OCL=34798
CL=34802

R=rsc
APPROVED=rsc
DELTA=1  (0 added, 1 deleted, 0 changed)
OCL=34799
CL=34801

TBR=r
OCL=34800
CL=34800

- fixed broken link to function literals section
- minor adjustments

R=r
DELTA=20  (1 added, 3 deleted, 16 changed)
OCL=34792
CL=34794