runtime: fix arm build
The current failure is:
fatal error: runtime: stack split during syscall
goroutine 2 [stack split]:
_si2v(0xb6ebaebc, 0x3b9aca00)
/usr/local/go/src/pkg/runtime/vlrt_arm.c:628 fp=0xb6ebae9c
runtime.timediv(0xf8475800, 0xd, 0x3b9aca00, 0xb6ebaef4)
/usr/local/go/src/pkg/runtime/runtime.c:424 +0x1c fp=0xb6ebaed4
Just adding textflag 7 causes the following error:
notetsleep: nosplit stack overflow
128 assumed on entry to notetsleep
96 after notetsleep uses 32
60 after runtime.futexsleep uses 36
4 after runtime.timediv uses 56
-4 after _si2v uses 8
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/
12001045