message: Use nehalem instead of haswell as target cpu
diff: @@ -320,7 +320,9 @@ fn build_isa(sess: &Session, enable_pic: bool) -> Box<dyn isa::TargetIsa + 'stat
  let flags = settings::Flags::new(flags_builder);
  let mut isa_builder = cranelift_codegen::isa::lookup(target_triple).unwrap();
  - isa_builder.enable("haswell").unwrap();
  + // Don't use "haswell", as it implies `has_lzcnt`.macOS CI is still at Ivy Bridge EP, so `lzcnt`
  + // is interpreted as `bsr`.
  + isa_builder.enable("nehalem").unwrap();
  isa_builder.finish(flags)
  }
  