Store libgccjit.so in a lib directory in the GCC CI tarball

src/bootstrap/src/core/build_steps/dist.rs

@@ -2481,7 +2481,7 @@ fn make_run(run: RunConfig<'_>) {
     fn run(self, builder: &Builder<'_>) -> Self::Output {
         let tarball = Tarball::new(builder, "gcc", &self.target.triple);
         let output = builder.ensure(super::gcc::Gcc { target: self.target });
-        tarball.add_file(output.libgccjit, ".", 0o644);
+        tarball.add_file(output.libgccjit, "lib", 0o644);
         tarball.generate()
     }
 }

src/bootstrap/src/core/build_steps/gcc.rs

@@ -115,8 +115,7 @@ fn try_download_gcc(builder: &Builder<'_>, target: TargetSelection) -> Option<Pa
         t!(gcc_stamp.write());
     }
 
-    // FIXME: put libgccjit.so into a lib directory in dist::Gcc
-    let libgccjit = root.join("libgccjit.so");
+    let libgccjit = root.join("lib").join("libgccjit.so");
     create_lib_alias(builder, &libgccjit);
     Some(libgccjit)
 }