A addressing mode folding enhancement:

A addressing mode folding enhancement:
Fold c2 in (x << c1) | c2 where (c2 < c1)
e.g.
int test(int x) {
  return (x << 3) + 7;
}

This can be codegen'd as:
leal 7(,%eax,8), %eax

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28550 91177308-0d34-0410-b5e6-96231b3b80d8