backend intro

Author: mark-i-m

src/SUMMARY.md

@@ -112,17 +112,17 @@
         - [Debugging](./mir/debugging.md)
     - [Constant evaluation](./const-eval.md)
         - [miri const evaluator](./miri.md)
+    - [Monomorphization](./backend/monomorph.md)
     - [Compiler Backend](./backend/backend.md)
-        - [Monomorphization](./backend/monomorph.md)
-        - [Lowering MIR](./backend/lowering-mir.md)
-        - [Code Generation](./backend/codegen.md)
-            - [Updating LLVM](./backend/updating-llvm.md)
-            - [Debugging LLVM](./backend/debugging.md)
-            - [Backend Agnostic Codegen](./backend/backend-agnostic.md)
-            - [Implicit Caller Location](./codegen/implicit-caller-location.md)
-        - [Profile-guided Optimization](./profile-guided-optimization.md)
-        - [Sanitizers Support](./sanitizers.md)
-        - [Debugging Support in Rust Compiler](./debugging-support-in-rustc.md)
+    - [Lowering MIR](./backend/lowering-mir.md)
+    - [Code Generation](./backend/codegen.md)
+        - [Updating LLVM](./backend/updating-llvm.md)
+        - [Debugging LLVM](./backend/debugging.md)
+        - [Backend Agnostic Codegen](./backend/backend-agnostic.md)
+        - [Implicit Caller Location](./codegen/implicit-caller-location.md)
+    - [Profile-guided Optimization](./profile-guided-optimization.md)
+    - [Sanitizers Support](./sanitizers.md)
+    - [Debugging Support in Rust Compiler](./debugging-support-in-rustc.md)
 
 ---
 

src/backend/backend.md renamed to src/part-5-intro.md

@@ -48,3 +48,4 @@ crate contains code specific to LLVM codegen.
 At a very high level, the entry point is
 [`rustc_codegen_ssa::base::codegen_crate`][codegen1]. This function starts the
 process discussed in the rest of this chapter.
+