* 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
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
