Rollup merge of #132750 - daltenty:daltenty/libs, r=jieyouxu

[AIX] handle libunwind native_libs

AIX should follow a similar path here to other libunwind platforms, with regards to system vs in-tree libunwind and the native lib search directories.

Having the right native lib search directories here is also required to get the correct default library search paths, due to some quirks of the AIX linker.

compiler/rustc_metadata/src/native_libs.rs

@@ -54,9 +54,13 @@ pub fn walk_native_lib_search_dirs<R>(
     // The targets here should be in sync with `copy_third_party_objects` in bootstrap.
     // FIXME: implement `-Clink-self-contained=+/-unwind,+/-sanitizers`, move the shipped libunwind
     // and sanitizers to self-contained directory, and stop adding this search path.
+    // FIXME: On AIX this also has the side-effect of making the list of library search paths
+    // non-empty, which is needed or the linker may decide to record the LIBPATH env, if
+    // defined, as the search path instead of appending the default search paths.
     if sess.target.vendor == "fortanix"
         || sess.target.os == "linux"
         || sess.target.os == "fuchsia"
+        || sess.target.is_like_aix
         || sess.target.is_like_osx && !sess.opts.unstable_opts.sanitizer.is_empty()
     {
         f(&sess.target_tlib_path.dir, false)?;

src/bootstrap/src/core/build_steps/compile.rs

@@ -330,7 +330,7 @@ fn copy_third_party_objects(
 
     if target == "x86_64-fortanix-unknown-sgx"
         || builder.config.llvm_libunwind(target) == LlvmLibunwind::InTree
-            && (target.contains("linux") || target.contains("fuchsia"))
+            && (target.contains("linux") || target.contains("fuchsia") || target.contains("aix"))
     {
         let libunwind_path =
             copy_llvm_libunwind(builder, target, &builder.sysroot_target_libdir(*compiler, target));