R=r, rsc
CC=golang-dev
https://golang.org/cl/4176046

R=r
CC=golang-dev
https://golang.org/cl/4000041

R=rsc
CC=golang-dev
https://golang.org/cl/3053041

currently, softfloat does not work and
there are some unsigned-to-float conversion errors.

R=rsc
CC=golang-dev
https://golang.org/cl/2886041

Because the SB is only good for 8k and Go programs
tend to have much more data than that, SB doesn't
save very much.  A fmt.Printf-based hello world program
has  360 kB text segment.  Removing SB makes the text
500 bytes (0.14%) longer.

R=ken2, r2, ken3
CC=golang-dev
https://golang.org/cl/2487042

R=rsc
APPROVED=rsc
DELTA=30  (30 added, 0 deleted, 0 changed)
OCL=35751
CL=35756

R=rsc
APPROVED=rsc
DELTA=4  (0 added, 0 deleted, 4 changed)
OCL=31016
CL=31126

R=rsc
APPROVED=rsc
DELTA=245  (167 added, 63 deleted, 15 changed)
OCL=30039
CL=30081

for linux system calls).

R=rsc
APPROVED=rsc
DELTA=3  (3 added, 0 deleted, 0 changed)
OCL=27325
CL=27328

R=rsc
APPROVED=rsc
DELTA=19042  (19042 added, 0 deleted, 0 changed)
OCL=26268
CL=26270