instrument-coverage for `wasm32-unknown-unknown` is broken in versions since 1.87.0

[Spxg]

I tried this code:

pub extern "C" fn foo(a: i32, b: i32) -> i32 {
    a + b
}

run:

RUSTFLAGS="-Cinstrument-coverage -Zno-profiler-runtime" cargo build --target wasm32-unknown-unknown

I expected to see this happen: The __llvm_profile_init symbol and other profiling symbols are present.

Instead, this happened: The __llvm_profile_init symbol and other profiling symbols are missing.

Introduced: nightly-2025-02-18

This might be related to the LLVM 20 upgrade:
ce36a966c#diff-eac3d5ef63f39b7914ae9015f31b8d87353ea8fbcd5b02a7335dd86c557e7625

Meta

rustc --version --verbose:

rustc 1.87.0-nightly (ce36a966c 2025-02-17)
binary: rustc
commit-hash: ce36a966c79e109dabeef7a47fe68e5294c6d71e
commit-date: 2025-02-17
host: aarch64-apple-darwin
release: 1.87.0-nightly
LLVM version: 20.1.0

[Spxg]

See llvm/llvm-project#111332 Amanieu/minicov#32