Add the "-s" flag to llvm-nm for Mach-O files that prints symbols only in
the specified section.  This is same functionality as darwin’s nm(1) "-s" flag.

There is one FIXME in the code and I’m all ears to anyone that can help me
with that.  This option takes exactly two strings and should be allowed
anywhere on the command line.  Such that "llvm-nm -s __TEXT __text foo.o"
would work. But that does not as the CommandLine Library does not have a
way to make this work as far as I can tell.  For now the "-s __TEXT __text"
has to be last on the command line.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212842 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel] Breakout intrinsic lowering into a separate function and add a target-hook.

Create a separate helper function for target-independent intrinsic lowering. Also
add an target-hook that allows to directly call into a target-sepcific intrinsic
lowering method. Currently the implementation is opt-in and doesn't affect
existing target implementations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212843 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel] Make isInTailCallPosition independent of SelectionDAG.

Break out the arguemnts required from SelectionDAG, so that this function can
also be used by FastISel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212844 91177308-0d34-0410-b5e6-96231b3b80d8