Update to LLVM 19

[alexcrichton]

This commit updates the LLVM submodule to the release/19.x branch from the previous 18.1.2 version

[alexcrichton]

This currently updates to llvmorg-19.1.0-rc1 as LLVM 19 isn't actually officially released yet. I get errors building locally that I don't know much about, so going to get some links on CI here to share with others.

[TerrorJack]

I guess you're seeing something like wasm-ld: error: build/wasm32-wasip2/libwasi-emulated-mman.so.a(mman.pic.o): undefined symbol: errno? It's due to 22b7b84860d39da71964c9b329937f2ee1d875ba that also ended up in the 19.x branch that I discovered today.

[sbc100]

I guess you're seeing something like wasm-ld: error: build/wasm32-wasip2/libwasi-emulated-mman.so.a(mman.pic.o): undefined symbol: errno? It's due to 22b7b84860d39da71964c9b329937f2ee1d875ba that also ended up in the 19.x branch that I discovered today.

Does this look like an linker bug, or is that symbol actually missing?

[yamt]

I guess you're seeing something like wasm-ld: error: build/wasm32-wasip2/libwasi-emulated-mman.so.a(mman.pic.o): undefined symbol: errno? It's due to 22b7b84860d39da71964c9b329937f2ee1d875ba that also ended up in the 19.x branch that I discovered today.

Does this look like an linker bug, or is that symbol actually missing?

cf. WebAssembly/wasi-libc#526

most of symbols seem to be the latter. (wasi-libc bug)

but some of them seems like a linker bug because they are expected to be provided by linker.
ie. __heap_base, __heap_end, __c_longjmp.

[TerrorJack]

WebAssembly/wasi-libc#526 is a much better solution than simply adding -Wl,--unresolved-symbols=import-dynamic in wasi-libc build logic, we should land that one first IMO.

[alexcrichton]

I moved the relevant bits here to #476 and the removal of -DLLVM_ENABLE_TERMINFO=OFF can happen when LLVM is actually updated.