remove code to add bound checks for simple array accesses, since those are already...

remove code to add bound checks for simple array accesses, since those are already covered by the check with the objectsize builtin
remove the comparison of objectsize with -1. since it's an unsigned comparison, it will always succeed if objectsize returns -1, which is enough to have the check removed

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156311 91177308-0d34-0410-b5e6-96231b3b80d8