[llvm] Reland: [llvm-cov][WebAssembly] Read `__llvm_prf_names` from data segments (PR #112569)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

FWIW, this reland of the patch does indeed seem like it still works for `llvm-cov` for reading the profile data from Windows (on the sample files from yesterday). I haven't tested building a full toolchain with this in place and running the compiler-rt tests again. I don't know about the rest of the big picture here, or @glandium's PGO setup.

https://github.com/llvm/llvm-project/pull/112569