Rollup merge of rust-lang#148709 - karolzwolak:bootstrap-override-lld-should-disable-self-contained-lld, r=Mark-Simulacrum

fix: disable self-contained linker when bootstrap-override-lld is set

Part of rust-lang#148708.

Makes `rust.bootstrap-override-lld` set to `true` or `"external"` disable self-contained linker — actually using linker from one's system.

Author: matthiaskrgr

src/bootstrap/src/utils/helpers.rs

@@ -430,6 +430,7 @@ pub fn linker_flags(
         match builder.config.bootstrap_override_lld {
             BootstrapOverrideLld::External => {
                 args.push("-Clinker-features=+lld".to_string());
+                args.push("-Clink-self-contained=-linker".to_string());
                 args.push("-Zunstable-options".to_string());
             }
             BootstrapOverrideLld::SelfContained => {