uses gcc to determine system header layouts and
emits simple C or Go.  see comment in main.c.

R=r
DELTA=1069  (1067 added, 0 deleted, 2 changed)
OCL=26682
CL=26880

cope better with p4 not found.

R=r
DELTA=3  (0 added, 0 deleted, 3 changed)
OCL=26877
CL=26879

R=r
DELTA=1926  (1727 added, 168 deleted, 31 changed)
OCL=26876
CL=26878

- removed left-over panic() call
- fixed a couple of bugs

R=r
OCL=26856
CL=26856

- commented public interface
- much better and very precise error messages
- much better tracing output
- many more checks (still permits more than just syntactically legal
  programs, but much more is checked that can be checked w/o semantic information)
- updated with respect to updated AST
- general cleanup throughout

Parser almost ready for move into lib/go.

R=r
OCL=26853
CL=26855

- remove ':' token from operator precedence levels

R=rsc
DELTA=25  (13 added, 8 deleted, 4 changed)
OCL=26850
CL=26854

R=r
DELTA=6  (6 added, 0 deleted, 0 changed)
OCL=26836
CL=26841

renamed PairExpr -> KeyValueExpr and PairExprList -> KeyValueList
(to match corresponding nodes in AST per rsc' suggestion)

- added a couple of TODOs

R=r,rsc
DELTA=10  (2 added, 0 deleted, 8 changed)
OCL=26837
CL=26840

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=26810
CL=26834

R=r
DELTA=4  (4 added, 0 deleted, 0 changed)
OCL=26797
CL=26814

- more comments on parser, various cleanups

TBR=r
OCL=26813
CL=26813

- permit scanner to run w/o error handler
- provide an error counter

R=iant
DELTA=43  (25 added, 0 deleted, 18 changed)
OCL=26804
CL=26812

R=iant
DELTA=4  (0 added, 0 deleted, 4 changed)
OCL=26802
CL=26811

R=r
DELTA=1509  (756 added, 751 deleted, 2 changed)
OCL=26799
CL=26801

R=r
DELTA=27  (25 added, 0 deleted, 2 changed)
OCL=26798
CL=26798

R=r
OCL=26794
CL=26794

- by moving Position into token, scanner dependencies
  are removed from several files
- clearer field names in token.Position, now possible to
  have a Pos() accessor w/o naming conflicts
- added Pos() accessor
- use anonymous token.Position field in AST nodes

R=r
DELTA=244  (28 added, 55 deleted, 161 changed)
OCL=26786
CL=26793

R=rsc
DELTA=22  (22 added, 0 deleted, 0 changed)
OCL=26779
CL=26792

- convert some functions into methods
- corresponding changes in pretty

R=r
DELTA=57  (3 added, 0 deleted, 54 changed)
OCL=26764
CL=26777

and expected review latency I needed to combine the CLs.

1. Made the 5* toolpath build using the go build
   system. Hooked the subdirectories to clean.bash but added a
   separate make5.bash for now. Minor massage to make the code
   more similar to the current structure of 6c/6a/6l.

2. Change all references from long to int32 in line with
   similar change for the other toolchains.

The end result is that 5c, 5a and 5l can now be compiled and
the executables start up properly. Haven't thrown any input at
them yet.

R=rsc
APPROVED=rsc
DELTA=1052  (392 added, 328 deleted, 332 changed)
OCL=26757
CL=26761

R=r
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=26738
CL=26753

R=r
OCL=26746
CL=26746

R=rsc,r
DELTA=309  (67 added, 51 deleted, 191 changed)
OCL=26611
CL=26745

DELTA=31  (31 added, 0 deleted, 0 changed)
OCL=26709
CL=26716

add code to handle 32-bit Mach-O and ELF binaries.

R=r
DELTA=452  (365 added, 29 deleted, 58 changed)
OCL=26696
CL=26712

add 8a 8c 8l to the build to keep us honest.

R=r
DELTA=33  (28 added, 0 deleted, 5 changed)
OCL=26694
CL=26711

remove debugging print.

R=r
DELTA=8  (0 added, 8 deleted, 0 changed)
OCL=26695
CL=26710

DELTA=26  (0 added, 0 deleted, 26 changed)
OCL=26703
CL=26705

R=gri,rsc
DELTA=48  (28 added, 11 deleted, 9 changed)
OCL=26630
CL=26701

R=r
OCL=26699
CL=26699

^ signed(const) becomes illegal
^ unsigned(const) becomes legal

R=r
OCL=26697
CL=26697

	install runtime lib in correct location.
	fix one bad type definition in defs.h.
	clear out $GOROOT/lib in clean.bash.

TBR=r
OCL=26691
CL=26691

out of malloc proper.

TBR=r
OCL=26689
CL=26689

TBR=r
OCL=26686
CL=26688

this change is much smaller if you ignore
the machine-generated defs.h.

TBR=r
OCL=26684
CL=26684

move out of arch-specific directory: only os-specific.
rm sys_types.h (unused).

TBR=r
OCL=26681
CL=26681

move darwin-amd64 specific code into runtime/darwin/amd64/
repeat for linux.

move rt0 into runtime.a instead of keeping a separate .6 file.
6l seems to have no problem with that.

TBR=r
OCL=26680
CL=26680

in favor of the lib9 compatibility layer.  no need for two.

now that mycreate is gone, .6 files are 0644 not 0755.

TBR=r
OCL=26679
CL=26679

into amd64/ directory.

split rt2_amd64.c into closure.c and traceback.c.

TBR=r
OCL=26678
CL=26678

R=ken
OCL=26664
CL=26664