Summary:
```
``!listsplat(a, size)``
A list value that contains the value ``a`` ``size`` times.
Example: ``!listsplat(0, 2)`` results in ``[0, 0]``.
```
I plan to use this in X86ScheduleBdVer2.td for LoadRes handling.
This is a little bit controversial because unlike every other binary operator
the types aren't identical.
Reviewers: stoklund, javed.absar, nhaehnle, craig.topper
Reviewed By: javed.absar
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60367
llvm-svn: 358117