[x86] Teach the new vector shuffle lowering to widen floating point
elements as well as integer elements in order to form simpler shuffle
patterns.

This is the primary reason why we were failing to match some of the
2-and-2 floating point shuffles such as PR21140. Even after fixing this
we need to support some extra patterns in the backend in order to match
the resulting X86ISD::UNPCKL nodes into the correct instructions. This
commit should fix PR21140 and includes more comprehensive testing of
insertion patterns in v4 shuffles.

Not all of the added tests are beautiful. For example, we don't have
clever instructions to insert-via-load in the integer domain. There are
also some places where we aren't sufficiently cunning with our use of
movq and movd, but that's future work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218911 91177308-0d34-0410-b5e6-96231b3b80d8
DI: Fold constant arguments into a single MDString

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218914 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-readobj: print COFF imported symbols

This patch defines a new iterator for the imported symbols.
Make a change to COFFDumper to use that iterator to print
out imported symbols and its ordinals.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218915 91177308-0d34-0410-b5e6-96231b3b80d8
Rename data -> Data


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218916 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "DI: Fold constant arguments into a single MDString"

This reverts commit r218914 while I investigate some bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218918 91177308-0d34-0410-b5e6-96231b3b80d8