[ARM] Enable useAA() for the in-order Cortex-R52

This option allows codegen (such as DAGCombine or MI scheduling) to use alias
analysis information, which can help with the codegen on in-order cpu's,
especially machine scheduling. Here I have done things the same way as AArch64,
adding a subtarget feature to enable this for specific cores, and enabled it for
the R52 where we have a schedule to make use of it.

Differential Revision: https://reviews.llvm.org/D48074

llvm-svn: 335249