Inline and remove Session::compile_status.

Because it's now simple enough that it doesn't provide much benefit.

Author: nnethercote

src/bin/miri.rs

@@ -68,7 +68,7 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
         queries: &'tcx rustc_interface::Queries<'tcx>,
     ) -> Compilation {
         queries.global_ctxt().unwrap().enter(|tcx| {
-            if tcx.sess.compile_status().is_err() {
+            if tcx.sess.dcx().has_errors().is_some() {
                 tcx.dcx().fatal("miri cannot be run on programs that fail compilation");
             }