Building libFuzzer i386 from compiler-rt releases

Hey all. I am able to build an i386 version of libclang_rt.fuzzer-i386.a with a local llvm (configured with -DLLVM_BUILD_32_BITS=ON). However, doing the same with a source archive provided by releases.llvm.org does not produce this artifact. Is this due to my system LLVM not being configured properly? Thanks.