[llvm] [TableGen] Use StringTable for searchable tables (PR #206252)

[Alexis Engelke via llvm-commits]

aengelke wrote:

> Would it make sense to create a table of strings across all tables being emitted?

I investigated and concluded that there'd be very little benefit. The only file with meaningful duplicates was SPIRV, because it stores several builtin infos twice (bad design, IMO). Otherwise, a merged string table would make it more difficult to use smaller string table offsets in the data structures for small tables later on.

https://github.com/llvm/llvm-project/pull/206252