[release-branch.r58] gopprof: update list of memory allocators

««« CL 4650048 / 09d52e36dab9
gopprof: update list of memory allocators

Also import new weblist command from Google version.

R=r, bradfitz
CC=golang-dev
https://golang.org/cl/4650048
»»»

R=rsc
CC=golang-dev
https://golang.org/cl/4654072