Fix metadata passing in link functions

- Pass metadata parameter through from NvvmCodegenBackend::link to link::link
- Use metadata.raw_bytes() instead of hardcoded empty array in create_archive
- Add metadata parameter to link_rlib function signature
- Properly thread metadata through the linking pipeline

Author: LegNeato

crates/rustc_codegen_nvvm/src/lib.rs

@@ -181,14 +181,15 @@ impl CodegenBackend for NvvmCodegenBackend {
         &self,
         sess: &rustc_session::Session,
         codegen_results: rustc_codegen_ssa::CodegenResults,
-        _metadata: rustc_metadata::EncodedMetadata,
+        metadata: rustc_metadata::EncodedMetadata,
         outputs: &config::OutputFilenames,
     ) {
         link::link(
             sess,
             &codegen_results,
             outputs,
             codegen_results.crate_info.local_crate_name.as_str(),
+            metadata,
         );
     }
 }

crates/rustc_codegen_nvvm/src/link.rs

@@ -110,6 +110,7 @@ pub fn link(
     codegen_results: &CodegenResults,
     outputs: &OutputFilenames,
     crate_name: &str,
+    metadata: rustc_metadata::EncodedMetadata,
 ) {
     debug!("Linking crate `{}`", crate_name);
     // largely inspired by rust-gpu
@@ -136,7 +137,7 @@ pub fn link(
                 out_filename.file_for_writing(outputs, OutputType::Exe, "", None);
             match crate_type {
                 CrateType::Rlib => {
-                    link_rlib(sess, codegen_results, &out_filename_file_for_writing);
+                    link_rlib(sess, codegen_results, &out_filename_file_for_writing, &metadata);
                 }
                 CrateType::Executable | CrateType::Cdylib | CrateType::Dylib => {
                     let _ = link_exe(
@@ -153,7 +154,7 @@ pub fn link(
     }
 }
 
-fn link_rlib(sess: &Session, codegen_results: &CodegenResults, out_filename: &Path) {
+fn link_rlib(sess: &Session, codegen_results: &CodegenResults, out_filename: &Path, metadata: &rustc_metadata::EncodedMetadata) {
     debug!("Linking rlib `{:?}`", out_filename);
     let mut file_list = Vec::<&Path>::new();
 
@@ -187,7 +188,7 @@ fn link_rlib(sess: &Session, codegen_results: &CodegenResults, out_filename: &Pa
     create_archive(
         sess,
         &file_list,
-        &[], // Metadata is no longer available in CodegenResults
+        metadata.raw_bytes(),
         out_filename,
     );
 }