wasm32-unknown-unknown does not link

[Victor Porton]

$ cat x.c
int main() {
  return 0;
}
$ clang --target=wasm32-unknown-unknown x.c
clang: error: unable to execute command: Executable "wasm-ld" doesn't exist!
clang: error: linker command failed with exit code 1 (use -v to see invocation)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: clang-10 1:10.0.0-4ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-53.59-generic 5.4.65
Uname: Linux 5.4.0-53-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.12
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Tue Nov 17 18:52:56 2020
InstallationDate: Installed on 2018-06-23 (877 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: llvm-toolchain-10
UpgradeStatus: Upgraded to focal on 2020-05-13 (188 days ago)

[Sylvestre Ledru (sylvestre)]

Fixed in https://tracker.debian.org/news/1289006/accepted-llvm-toolchain-13-11301rc1-1exp2-source-into-experimental/

Note that it won't be enough, it needs the runtime:
clang-13 --target=wasm32-unknown-unknown foo.c
wasm-ld: error: cannot open crt1.o: No such file or directory
wasm-ld: error: unable to find library -lc
wasm-ld: error: unable to find library -lgcc
clang: error: linker command failed with exit code 1 (use -v to see invocation)