Try to read #[inline(always)] MIR bodies but don't actually inline

Author: vlad20012

compiler/rustc_mir_transform/src/inline.rs

@@ -48,7 +48,8 @@ impl<'tcx> MirPass<'tcx> for Inline {
         }
 
         match sess.mir_opt_level() {
-            0 | 1 => false,
+            0 => false,
+            1 => true,
             2 => {
                 (sess.opts.optimize == OptLevel::Default
                     || sess.opts.optimize == OptLevel::Aggressive)
@@ -173,6 +174,10 @@ impl<'tcx> Inliner<'tcx> {
         let callee_body = self.tcx.instance_mir(callsite.callee.def);
         self.check_mir_body(callsite, callee_body, callee_attrs)?;
 
+        if self.tcx.sess.mir_opt_level() == 1 {
+            return Err("mir_opt_level == 1");
+        }
+
         if !self.tcx.consider_optimizing(|| {
             format!("Inline {:?} into {:?}", callsite.callee, caller_body.source)
         }) {