Reland "Fixed environment assignment for LCheckNonSmi."

Now with (hopefully correct) ARM64 part... :-}

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/225313003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20495 ce2b1a6d-e550-0410-aec6-3dcde31c8c00