[JuliaLowering] `ssaflags` support (#61792)

Fill in CodeInfo ssaflags, which was an outstanding TODO. This means
`inbounds`, `inline`, `noinline`, and `purity` should now be fully
supported, where previously we only supported the cases they expanded to
`(meta $symbol)`. The implementation should match
`jl_new_code_info_from_ir` in method.c.

Tests mostly botted.

Certain internal errors should now be fixed: fix #61737, fix
https://github.com/JuliaLang/JuliaLowering.jl/issues/128