ART: Fix Thumb2 literal fixup.

When processing a load literal during fixup, we use the
current code size to determine whether we need to add the
padding before literals. However, this may change by the end
of the fixup, yet we didn't recalculate to see if the load
literal is pushed out of range.

Instead of making the load literal fixup also depend on all
preceding fixups, add an extra pass over literals when we
need the padding and repeat the fixup loop if needed.

Change-Id: Ia21d660486167a2dcb1ad4afe8acc669b4af669d