[lld] [ELF] Making cdsort default for function reordering (PR #68638)

[via llvm-commits]

spupyrev wrote:

Can we apply the same optimization for cdsort as in https://github.com/llvm/llvm-project/pull/68617? (ie limiting the size of the max chain to 512). Block reordering becomes 50x faster on some instances after the change, without sacrificing the quality. I am happy to test this too, if you share (some version of) the problematic call graph.
Btw, cdsort is on by default in BOLT for ~5 years now. Likely something is off with the call graphs coming from the compiler.

https://github.com/llvm/llvm-project/pull/68638