C: add Michael Matloob (Google CLA)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7343043
go/parser: stop ParseFile after ten errors.

There wil be a panic if more than ten errors are encountered. ParseFile
will recover and return the ErrorList.

Fixes issue 3943.

R=golang-dev, gri
CC=golang-dev
https://codereview.appspot.com/7307085

Committer: Robert Griesemer <gri@golang.org>