[llvm] [LLVM] Factor disabled Libcalls into the initializer (PR #98421)

[Shilei Tian via llvm-commits]

shiltian wrote:

But you did factor them to some degree right? It looks like they are categorized in a mixture of multiple ways. It is neither based on the lib call (like one block for one lib call, or one block for a series of lib calls), nor on the triple, because some triples definitely appear multiple times.

https://github.com/llvm/llvm-project/pull/98421