Fix #8754 again.

This time, we carefully initialize the GC stats only if they're not
already initialized - this way the user can override them (e.g. `+RTS -t
--machine-readable`).

Signed-off-by: Austin Seipp <austin@well-typed.com>

(cherry picked from commit c72e8898447b2a8e55f2d16594b5944c2ae13e24)
Fix installation of ghc-split (#8760)

The rules weren't correctly setting INSTALL_TOPDIRS, and on top of that
the dependencies were wrong when BINDIST=YES.

Authored-by: Evan Hauck <khyperia@live.com>
Authored-by: Austin Seipp <austin@well-typed.com>
Signed-off-by: Austin Seipp <austin@well-typed.com>

(cherry picked from commit beac5252d444bafb0722bc6d13c6dd2d49a12070)