[RFC] Enable DFA JumpThreading pass by default

DFA JumpThreading adds jump-threading optimization for deterministic finite automata which are implemented using switch statements. We would like to enable it by default.

The pass was added in 2021 here: ⚙ D99205 Add jump-threading optimization for deterministic finite automata
Also related: Improved jump-threading in LLVM for finite state automata

I have done testing on AArch64 and am seeing nice performance benefits and no regressions.
EEMBC/Coremark: +16% speedup
SPEC2017/omnetpp: +4% speedup
SPEC2006/libquantum: +2-3% speedup

Additionally our correctness testing suite shows no failures or compiler crashes.

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