Revert "Add a soft-deopt in keyed element access when current IC is pre-monomorphic and no type feedback was collected."

This reverts commit r17288 for breaking the mjsunit/unbox-double-arrays
test on almost every platform.

TBR=hpayer@chromium.org

Review URL: https://codereview.chromium.org/32373002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17289 ce2b1a6d-e550-0410-aec6-3dcde31c8c00