Do not create a HBoundType when the instruction is non-null.

We don't need to refine the type after a null check, if the
instruction is known non null or null. As a side effect, this
avoids replacing HLoadClass instructions with HBoundType instructions.

bug:22116987

Change-Id: I565ae95db5a64faec30e026674636e398e0bf445
3 files changed