Improve BasicAA CS-CS queries

BasicAA contains knowledge of certain intrinsics, such as memcpy and memset,
and uses that information to form more-accurate answers to CallSite vs. Loc
ModRef queries. Unfortunately, it did not use this information when answering
CallSite vs. CallSite queries.

Generically, when an intrinsic takes one or more pointers and the intrinsic is
marked only to read/write from its arguments, the offset/size is unknown. As a
result, the generic code that answers CallSite vs. CallSite (and CallSite vs.
Loc) queries in AA uses UnknownSize when forming Locs from an intrinsic's
arguments. While BasicAA's CallSite vs. Loc override could use more-accurate
size information for some intrinsics, it did not do the same for CallSite vs.
CallSite queries.

This change refactors the intrinsic-specific logic in BasicAA into a generic AA
query function: getArgLocation, which is overridden by BasicAA to supply the
intrinsic-specific knowledge, and used by AA's generic implementation. This
allows the intrinsic-specific knowledge to be used by both CallSite vs. Loc and
CallSite vs. CallSite queries, and simplifies the BasicAA implementation.

Currently, only one function, Mac's memset_pattern16, is handled by BasicAA
(all the rest are intrinsics). As a side-effect of this refactoring, BasicAA's
getModRefBehavior override now also returns OnlyAccessesArgumentPointees for
this function (which is an improvement).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212572 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64: Better codegen for loading from __fp16.

Loading will generally extend to an f32 or an 64, so make sure
to match those patterns directly to load into the FPR16 register
class directly rather than going through the integer GPRs.

This also eliminates an extra step in the convert-to-f64 path
which was first converting to f32 and then to f64 from there.

rdar://17594379

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212573 91177308-0d34-0410-b5e6-96231b3b80d8
Changed the lvm-nm alias "-s" for -print-armap to "-M".
This will allow the "-s" flag to implemented in the future as it
is in darwin’s nm(1) to list symbols only in the specified section.

Given a LGTM by Shankar Easwaran who originally implemented
the support for lvm-nm’s -print-armap and archive map symbols.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212576 91177308-0d34-0410-b5e6-96231b3b80d8
MipsTargetStreamer.h: Avoid "using" to appease msc17.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212577 91177308-0d34-0410-b5e6-96231b3b80d8