Use DefaultAttrsIntrinsics for most ARM intrinsics. This adds the WillReturn, NoSync, NoFree and NoCallback attributes and is needed to avoid regressions in the future.
I've switched to DefaultAttrIntrinsics for everything doing arithmetic and load/store. I've left some TODOs in cases where all DefaultsAttrs are not correct (e.g. ldrex etc are clearly not nosync) or it wasn't entirely obvious to me (e.g. stuff interacting with a coprocessor).
Given [WillReturn, NoSync, NoFree and NoCallback], these FP intrinsics sounds OK.