Following integration of https://github.com/openjdk/jdk/pull/29039, a bot review identifed two typos in the integrated code.

1. src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp: L2831
          assert(ac = ShenandoahHeapRegion::region_size_bytes(),
                     "Cannot move to old unless entire region is in alloc capacity");
    Is this assignment expected here?

2. src/hotspot/share/gc/shenandoah/heuristics/shenandoahAdaptiveHeuristics.cpp: L742
        weighted_y_sum = y_array[i] * sample_weight;
Should this be changed to
        weighted_y_sum += y_array[i] * sample_weight;

Fix both errors.