Try both ways to fold an add together. This allows us to generate this code

Try both ways to fold an add together.  This allows us to generate this code

        imul %EAX, %EAX, 400
        add %ECX, %EAX
        add %ESI, DWORD PTR [%ECX + 4*%EDX]
        inc %EDX
        cmp %EDX, 100

instead of this:

        imul %EAX, %EAX, 400
        add %ECX, %EAX
        mov %EAX, %EDX
        shl %EAX, 2
        add %ECX, %EAX
        add %ESI, DWORD PTR [%ECX]
        inc %EDX
        cmp %EDX, 100

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19513 91177308-0d34-0410-b5e6-96231b3b80d8