We add a new ScopeType, ScopeType.Script. The scope with
ScopeType.Script is always present in the scope chain (ScopeIterator
fakes it if neededi - i.e. if ScriptContext for a script has not been
allocated since that script has no lexical declarations).
ScriptScope reflects ScriptContextTable.

R=yurys@chromium.org,yangguo@chromium.org
BUG=v8:3690
LOG=N

Review URL: https://codereview.chromium.org/726643002

Cr-Commit-Position: refs/heads/master@{#25383}

R=rossberg@chromium.org

BUG=v8:2355
LOG=Y

Review URL: https://codereview.chromium.org/573963003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23974 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=dslomov@chromium.org
BUG=

Review URL: https://codereview.chromium.org/479543003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23272 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/247003004


Review URL: https://codereview.chromium.org/256733004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20964 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This reverts commit r20921 for breaking the ARM/ARM64 bots.

TBR=wingo@igalia.com

Review URL: https://codereview.chromium.org/255563003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20923 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/247003004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20921 ce2b1a6d-e550-0410-aec6-3dcde31c8c00