saving of sp was too far away from use in scanstack;
the stack had changed since the sp was saved.

R=r
DELTA=9  (4 added, 2 deleted, 3 changed)
OCL=32232
CL=32237

function calling.  Implement a type compiler and named types.
Implement a universal scope containing built-in named types,
and some built-in constants.  Implement a simple virtual
machine for executing statements and single-valued return.

Fix many places that incorrectly dealt with named types.  In
particular, the Type.Zero methods now use the type's bit count
to determine the appropriate value representation.  As a
result, a bit count of 0 now means architecture-dependent and
bounded types use unsafe.Sizeof to determine the correct
bounds.  Previously, the bounds on a 32-bit machine would have
been wrong.

Eliminated Type.compatible, since the implementation is
equivalent for all types.  Added Type.rep that shallowly
strips named types.  Replaced almost all uses of Type.literal
with Type.rep.

Fix implementation of assign-op's so it only evaluates the
left side once.  As part of this, there is now a generic way
to separate out the effect and value of an expression.

R=rsc
APPROVED=rsc
DELTA=1530  (1244 added, 68 deleted, 218 changed)
OCL=32184
CL=32230

TBR=r
OCL=32225
CL=32225

R=rsc
DELTA=298  (202 added, 0 deleted, 96 changed)
OCL=32006
CL=32224

R=gri
DELTA=2  (2 added, 0 deleted, 0 changed)
OCL=32214
CL=32223

R=r,iant
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=32215
CL=32222

R=r
APPROVED=gri
DELTA=23  (23 added, 0 deleted, 0 changed)
OCL=32106
CL=32189

fails without crashing.

R=gri
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=32164
CL=32171

so that golden.out does not include
the name of the compiler (which is
arch-specific and shows up in diffs).

R=r,iant
DELTA=3  (0 added, 0 deleted, 3 changed)
OCL=31980
CL=31983

if there is a goroutine waiting to run
and the init goroutine enters a system call,
entersyscall was trying to kick off a new
scheduler for the other goroutine, causing
a panic (new goroutines can't run until main.main).

R=r
DELTA=32  (32 added, 0 deleted, 0 changed)
OCL=31982
CL=31982

R=r
DELTA=51  (14 added, 24 deleted, 13 changed)
OCL=31968
CL=31971

just like ONAME etc.

R=ken
OCL=31964
CL=31964

R=rsc
DELTA=16  (9 added, 3 deleted, 4 changed)
OCL=31956
CL=31963

R=rsc
APPROVED=rsc
DELTA=591  (497 added, 76 deleted, 18 changed)
OCL=31933
CL=31955

as go is concerned).  the -d flag is now flipped; as on the mac, -d disables dynamic.

much remains to be improved to move the output closer to the gcc format.

R=rsc
DELTA=366  (310 added, 30 deleted, 26 changed)
OCL=31929
CL=31951

R=rsc
DELTA=3  (0 added, 0 deleted, 3 changed)
OCL=31944
CL=31950

- use array for common small values
- integer.go, rational.go don't contain changes besides the added file header

R=rsc
DELTA=1475  (748 added, 713 deleted, 14 changed)
OCL=31939
CL=31942

R=rsc
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=31916
CL=31937

R=r
DELTA=12  (12 added, 0 deleted, 0 changed)
OCL=31915
CL=31936

R=rsc
DELTA=195  (146 added, 1 deleted, 48 changed)
OCL=31895
CL=31931

all type-specific value functions, and use ZeroVal to create
new frames.  Remove Value.Type; it was unused and difficult
for values with composite types.  Add Value.Assign methods.

R=rsc
APPROVED=rsc
DELTA=282  (135 added, 90 deleted, 57 changed)
OCL=31894
CL=31930

R=rsc
DELTA=5  (0 added, 0 deleted, 5 changed)
OCL=31900
CL=31900

Some cleanup.  Elem() on PtrType is now just Elem and matches
with ArrayType.  Generators now switch over the result type
instead of the operand type.  Delete unused diag function.

R=rsc
APPROVED=rsc
DELTA=281  (219 added, 18 deleted, 44 changed)
OCL=31876
CL=31891

R=ken
OCL=31890
CL=31890

R=gri
APPROVED=gri
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=31879
CL=31886

the n argument to strncat is the maximum
number of bytes to read from the src,
not the total size of the destination.

R=ken
OCL=31871
CL=31875

R=ken
OCL=31868
CL=31874

R=r
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=31863
CL=31870

- corresponding test cases
- some cleanups

R=rsc
DELTA=173  (68 added, 3 deleted, 102 changed)
OCL=31866
CL=31869

R=ken
OCL=31865
CL=31867

R=rsc
DELTA=68  (21 added, 28 deleted, 19 changed)
OCL=31857
CL=31864

make endianness explicit when writing values.

R=rsc
DELTA=129  (37 added, 7 deleted, 85 changed)
OCL=31826
CL=31854

R=rsc
DELTA=51  (41 added, 0 deleted, 10 changed)
OCL=31815
CL=31818

them as we go.

Lots of bug fixes.  Let the parser toss illegal character and
string literals.  Compile unary + correctly.  Allow float OP
ideal.  Compile unary * correctly.  Implement min and max float
values.

R=rsc
APPROVED=rsc
DELTA=64  (29 added, 7 deleted, 28 changed)
OCL=31811
CL=31814

R=rsc
DELTA=181  (93 added, 63 deleted, 25 changed)
OCL=31802
CL=31812

- code cleanup

R=rsc,austin
DELTA=28  (12 added, 2 deleted, 14 changed)
OCL=31808
CL=31810

   explicit.go:21:5: error: incompatible types in assignment (need explicit conversion)
   explicit.go:26:5: error: incompatible types in assignment (type has no methods)
   explicit.go:27:5: error: incompatible types in assignment (need explicit conversion)
   explicit.go:30:6: error: incompatible types in assignment (need explicit conversion; missing method ‘N’)
   explicit.go:33:7: error: invalid type conversion (need explicit conversion; missing method ‘N’)
   explicit.go:36:5: error: incompatible types in assignment

R=rsc
DELTA=1  (0 added, 0 deleted, 1 changed)
OCL=31805
CL=31807

R=gri
APPROVED=gri
DELTA=30  (25 added, 0 deleted, 5 changed)
OCL=31796
CL=31799

R=rsc
DELTA=130  (68 added, 6 deleted, 56 changed)
OCL=31798
CL=31798

literals and when the parser hits an unexpected EOF.  Also,
disallow newlines in character literals.

R=gri
APPROVED=gri
DELTA=23  (15 added, 1 deleted, 7 changed)
OCL=31790
CL=31797