Curiosity: What accounts for the growth in the RTS in 9.2?

I was chatting with a colleague who asked "How big is GHC's run-time system." In the spirit of "look and find out," I found this: nr@homedog ~/.ghcup> ls -hl **HSrts.a -rw-r--r-- 1 nr nr 8.7M Sep 27 16:13 ghc/8.10.7/lib/ghc-8.10.7/rts/libHSrts.a -rw-r--r-- 1 nr nr 8.8M Sep 27 16:36 ghc/9.0.1/lib/ghc-9.0.1/rts/libHSrts.a -rw-r--r-- 1 nr nr 11M Jan 24 15:06 ghc/9.2.1/lib/ghc-9.2.1/rts/libHSrts.a All these binaries were installed by ghcup using the default settings. Does anybody know what accounts for the big jump from 9.0 to 9.2? Norman