[DAGCombiner] Add general constant vector support to (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)

We already supported scalar constant / splatted constant vector - now accepts any (non opaque) constant scalar / vector

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284613 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed