codegen_llvm: avoid `Deref` impls w/ extern type

`rustc_codegen_llvm` relied on `Deref` impls where `Deref::Target` was
or contained an extern type - in my experimental implementation of
rust-lang/rfcs#3729, this isn't possible as the `Target` associated
type's `?Sized` bound cannot be relaxed backwards compatibly (unless we
come up with some way of doing this).

In later pull requests with the rust-lang/rfcs#3729 implementation,
breakage like this could only occur for nightly users relying on the
`extern_types` feature.

Upstreaming this to avoid needing to keep carrying this patch locally,
and I think it'll necessarily need to change eventually.

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
index 99906ea7bce..05a2cd1c5a3 100644
--- a/compiler/rustc_codegen_llvm/src/back/lto.rs
+++ b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -793,7 +793,9 @@ pub(crate) unsafe fn optimize_thin_module(
         {
             let _timer =
                 cgcx.prof.generic_activity_with_arg("LLVM_thin_lto_rename", thin_module.name());
-            unsafe { llvm::LLVMRustPrepareThinLTORename(thin_module.shared.data.0, llmod, target) };
+            unsafe {
+                llvm::LLVMRustPrepareThinLTORename(thin_module.shared.data.0, llmod, target.raw())
+            };
             save_temp_bitcode(cgcx, &module, "thin-lto-after-rename");
         }
 
@@ -823,7 +825,7 @@ pub(crate) unsafe fn optimize_thin_module(
             let _timer =
                 cgcx.prof.generic_activity_with_arg("LLVM_thin_lto_import", thin_module.name());
             if unsafe {
-                !llvm::LLVMRustPrepareThinLTOImport(thin_module.shared.data.0, llmod, target)
+                !llvm::LLVMRustPrepareThinLTOImport(thin_module.shared.data.0, llmod, target.raw())
             } {
                 return Err(write::llvm_err(dcx, LlvmError::PrepareThinLtoModule));
             }