Javran Cheng authored May 13, 2015 and Erik de Castro Lopo committed May 13, 2015

Fix fragile tests according to comment 13 of #9579 (by @bherzog)

Done by capturing stderr and replace `xx bytes` with `NUM bytes`
(literal).

Some numbers like `(1 MB)` would still remain, but I think
it's safe to assume the actual difference in bytes (on different
architectures) is too small to have an effect on the rounded megabyte
value.

Test Plan: validate

Reviewers: erikd, austin

Reviewed By: erikd, austin

Subscribers: erikd, bgamari, thomie, bherzog

Differential Revision: https://phabricator.haskell.org/D882

GHC Trac Issues: #9579