ONe more iteration of PcDesacriptor iterator imporvement: do not copy record but access individual values when needed.

R=hausner@google.com

Review URL: https://codereview.chromium.org//403643002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38408 260f80e4-7a28-3924-810f-c04153c831b5
Profiler cleanup

BUG=
R=asiva@google.com

Review URL: https://codereview.chromium.org//397163002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38409 260f80e4-7a28-3924-810f-c04153c831b5
remove instanceof DartElement code blocks because there are no instances

BUG=
R=scheglov@google.com

Review URL: https://codereview.chromium.org//408513002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38410 260f80e4-7a28-3924-810f-c04153c831b5
Fix build breakage introduced in r38409

BUG=

Review URL: https://codereview.chromium.org//403003003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38411 260f80e4-7a28-3924-810f-c04153c831b5
Really fix the build

BUG=

Review URL: https://codereview.chromium.org//408493004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38412 260f80e4-7a28-3924-810f-c04153c831b5
Skip utf85_test on simarm64 because it timesout

BUG=

Review URL: https://codereview.chromium.org//398273004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38413 260f80e4-7a28-3924-810f-c04153c831b5
Small tuning of unboxing heuristic.

Review URL: https://codereview.chromium.org//403043002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@38414 260f80e4-7a28-3924-810f-c04153c831b5