[DeLICM] Fix wrong assumed access execution order.

ForwardOpTree may already transform a scalar access to an array
accesses. The access remains implicit (isOriginalScalarKind(), meaning
that the access is always executed at the begin/end of a statement), but
targets an array (isLatestArrayKind(), which is unrelated to whether the
execution is implicit/explicit).

Fix by properly using isOriginalXXX() to determine execution order.

This fixes the buildbots on MultiSource/Benchmarks/DOE-ProxyApps-C/miniGMG.

llvm-svn: 316995