[llvm] [AsmPrinter] Emit STT_OBJECT type and size for jump tables (PR #214170)

[Sam Elliott via llvm-commits]

lenary wrote:

To provide some context:

GCC also does not emit any elf-specific information about jump tables: https://godbolt.org/z/nvP3fz9Y7

I'm working on some tooling for analysing elf files, especially what's contributing to their size. With RISC-V's relaxation, there are lots of local symbols (of `STT_NOTYPE`) that are just for various relaxation, and currently these are hard to differentiate from the local symbols that denote the start of jump tables. This change makes it much easier to come up with a heuristic for discarding irrelevant symbols, and I think follows the ELF semantics more closely.

https://github.com/llvm/llvm-project/pull/214170