Fix test driver python3 compatibility issues

Summary:
Fixes python3 compatibility issues by replacing filter with a list
comperhension and a potential issue with python2 when override_flags
would be an empty list.

Reviewers: austin, thomie

Reviewed By: austin, thomie

Subscribers: thomie, carter, simonmar, mlen

Differential Revision: https://phabricator.haskell.org/D399

GHC Trac Issues: #9230
Add notes on change to hGetContents semantics

Summary:
Additionally, move Unicode 7.0 update notice from the compiler
section to the base libraries section.

Reviewers: austin

Reviewed By: austin

Subscribers: thomie, carter, simonmar

Projects: #ghc

Differential Revision: https://phabricator.haskell.org/D401
Fixed missing trailing newline bug in pretty printer

Summary:
Pretty printer didn't produce trailing newline in strings in error
messages.

Reviewers: simonpj, austin

Reviewed By: austin

Subscribers: thomie, carter, simonmar, mlen

Differential Revision: https://phabricator.haskell.org/D405

GHC Trac Issues: #9681