Add missing Debuginfo to PDB debug file on windows.

Set Arg0 and CommandLineArgs in MCTargetoptions so LLVM outputs correct CL and CMD in LF_DEBUGINFO instead of empty/invalid values.

compiler/rustc_interface/src/interface.rs

@@ -279,6 +279,12 @@ pub struct Config {
 
     /// Registry of diagnostics codes.
     pub registry: Registry,
+
+    /// All commandline args used to invoke the compiler, with @file args fully expanded.
+    /// This will only be used within debug info, e.g. in the pdb file on windows
+    /// This is mainly useful for other tools that reads that debuginfo to figure out
+    /// how to call the compiler with the same arguments.
+    pub expanded_args: Vec<String>,
 }
 
 // JUSTIFICATION: before session exists, only config
@@ -317,6 +323,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
                 config.make_codegen_backend,
                 registry.clone(),
                 config.ice_file,
+                config.expanded_args,
             );
 
             if let Some(parse_sess_created) = config.parse_sess_created {

compiler/rustc_interface/src/tests.rs

@@ -68,6 +68,7 @@ fn mk_session(handler: &mut EarlyErrorHandler, matches: getopts::Matches) -> (Se
         None,
         "",
         None,
+        Default::default(),
     );
     (sess, cfg)
 }

compiler/rustc_interface/src/util.rs

@@ -71,6 +71,7 @@ pub fn create_session(
     >,
     descriptions: Registry,
     ice_file: Option<PathBuf>,
+    expanded_args: Vec<String>,
 ) -> (Session, Box<dyn CodegenBackend>) {
     let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
         make_codegen_backend(&sopts)
@@ -113,6 +114,7 @@ pub fn create_session(
         target_override,
         rustc_version_str().unwrap_or("unknown"),
         ice_file,
+        expanded_args,
     );
 
     codegen_backend.init(&sess);