Build the trie by performing a three-way radix quicksort: We start by

sorting the strings by their first characters, then sort the strings

with the same first characters by their second characters, and so on

recursively. Each time the prefixes diverge, we add a node to the trie.

Thanks to @ruiu for the idea.

I used llvm-mc's radix quicksort implementation as a starting point. The

trie offset fixpoint code was taken from

MachONormalizedFileBinaryWriter.cpp.

Depends on D76908.