G1: Fill BOTs for Survivor-turned-to-Old regions in full gc

in JDK-8262068, we have an enhancement for full gc which will skip compacting some regions with high survivor ratio. There might be some young regions among these skipped regions. These young regions are not filled with BOTs info as they're young.
But after full GC these young regions will become old regions, and the BOTs info is better to be filled for performance consideration.