[llvm] Reenable JumpTableToSwitch pass by default (PR #83229)

[David Spickett via llvm-commits]

DavidSpickett wrote:

Final time for compiling the reproducer `JumpTableSizeThreshold`  9 was 1h52m17s.

If you make reproducers from the problematic files, I am happy to try them on our hardware if that helps.

Also if you find anything that Flang could do to reduce its compile time (regardless of this pass), I have colleagues working on it who might be able to implement that. We're probably stuck with the overall design but perhaps there's some small things we can do to help the compiler.

https://github.com/llvm/llvm-project/pull/83229