[llvm] [CodeGen] Introduce Static Data Splitter pass (PR #122183)

[Mingming Liu via llvm-commits]

https://github.com/mingmingl-llvm commented:

The updated test case is simpler by tuning down `-min-jump-table-entries` (from a default of 4 to 2 for x86), and function `@foo` has four jump tables (hot and cold interleaved to make {`LJTI0_0`, `LJTI0_2`} hot and the other two cold) for section testing.

Thanks for all the reviews and please take a another look!

https://github.com/llvm/llvm-project/pull/122183