A performance regression in array literal creation was caused by refactoring that eliminated a special fast case for shallow arrays. At the same time the general case got a bit slower. This CL restores most of the performance without coding the special fast case. The virtual dispatching is unnecessary because we know what we want to do at compile time. A flag was added to Runtime::CreateArrayLiteral. The flags delivers information about shallowness but also whether or not allocation mementos should be created. This is useful for crankshafted code.

BUG=v8:3008
LOG=Y
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/77293003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18046 ce2b1a6d-e550-0410-aec6-3dcde31c8c00