Makes build unnecessarily slower. Will fix the parser instead.

««« original CL description
runtime/pprof: run TestGoroutineSwitch for longer

Short test now takes about 0.5 second here.

Fixes #6417.

The failure was also seen on our builders.

R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/13321048
»»»

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13720048