Fix type analysis of the keyword "dynamic".

The type of "dynamic" isn't "dynamic", it's "Type".

BUG=dartbug.com/18731
R=scheglov@google.com

Review URL: https://codereview.chromium.org//680423003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41477 260f80e4-7a28-3924-810f-c04153c831b5
Properly restore context when leaving visitor functions in ErrorVerifier.

BUG=dartbug.com/15565
R=scheglov@google.com

Review URL: https://codereview.chromium.org//702623002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41478 260f80e4-7a28-3924-810f-c04153c831b5