Auto merge of rust-lang#138250 - jieyouxu:ios-mitigation, r=<try>

Use `/usr/bin/strip` on macOS -> iOS cross as a temporary workaround

Crude workaround for <rust-lang#138212> to unblock nightly macOS-to-iOS cross builds. This reintroduces the "hard-coded strip" workaround (but only for iOS) that was initially introduced in rust-lang#130781.

Looks like LLVM 20's initial `llvm-objcopy` version that we ship as `rust-objcopy` may be producing stripped iOS binaries with invalid offsets that fail iOS platform consistency checks.

For the time being, use macOS system strip when cross-compiling from macOS -> iOS at `/usr/bin/strip` which should be available (unlike Linux -> macOS cross where this is not guaranteed to be available, partially why we are shipping `llvm-objcopy` in the first place[^linux-darwin-cross]) that shouldn't have this offset problem.

### Alternatives

- We *could* also try to use a `strip` from PATH. *However*, that can regress iOS users if they have broken homebrew binutils strip in their PATH that take precedence over a "good" strip.
- We could also wait for upstream `llvm-objcopy` fixes.

### Review and testing advice

I don't have access to either macOS or iOS platforms, and I can't really write a test for this. This will need to be tested manually.

r? `@davidtwco` (or reroll)
cc *-apple-ios target maintainers `@badboy` `@deg4uss3r` `@madsmtm`

try-job: dist-apple-various
try-job: dist-x86_64-apple
try-job: dist-aarch64-apple

[^linux-darwin-cross]: rust-lang#131206

Author: bors

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1046,7 +1046,18 @@ fn link_natively(
     let strip = sess.opts.cg.strip;
 
     if sess.target.is_like_osx {
-        let stripcmd = "rust-objcopy";
+        let stripcmd = if sess.host.os == "macos" && sess.target.os != "macos" {
+            // FIXME(#138212): properly fix `llvm-objcopy` upstream when stripping iOS binaries
+            // (seemingly producing stripped binaries with incorrect offsets that fail platform
+            // consistency checks). This can only be used on macOS -> iOS cross because other linux
+            // hosts may not have a (good) system strip in this location.
+            //
+            // See upstream bug report <https://github.com/llvm/llvm-project/issues/130472>.
+            "/usr/bin/strip"
+        } else {
+            "rust-objcopy"
+        };
+
         match (strip, crate_type) {
             (Strip::Debuginfo, _) => {
                 strip_with_external_utility(sess, stripcmd, out_filename, &["--strip-debug"])