Teach the dag mechanism that this:

Teach the dag mechanism that this:

long long test2(unsigned A, unsigned B) {
        return ((unsigned long long)A << 32) + B;
}

is equivalent to this:

long long test1(unsigned A, unsigned B) {
        return ((unsigned long long)A << 32) | B;
}

Now they are both codegen'd to this on ppc:

_test2:
        blr

or this on x86:

test2:
        movl 4(%esp), %edx
        movl 8(%esp), %eax
        ret

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21231 91177308-0d34-0410-b5e6-96231b3b80d8