add -mrelax-relocations=no to i686-musl and i586-gnu

I've been experiencing #34978 with these two targets. This applies the
hack in #35178 to these targets as well.

src/bootstrap/lib.rs

@@ -858,8 +858,12 @@ impl Build {
         // This is a hack, because newer binutils broke things on some vms/distros
         // (i.e., linking against unknown relocs disabled by the following flag)
         // See: https://github.com/rust-lang/rust/issues/34978
-        if target == "x86_64-unknown-linux-musl" {
-            base.push("-Wa,-mrelax-relocations=no".into());
+        match target {
+            "i586-unknown-linux-gnu" |
+            "i686-unknown-linux-musl" |
+            "x86_64-unknown-linux-musl" => {
+                base.push("-Wa,-mrelax-relocations=no".into());
+            }
         }
         return base
     }