fix most compiler/ doctests

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -396,15 +396,15 @@ impl Drop for Linker<'_> {
 ///
 /// At a high level Thin LTO looks like:
 ///
-///     1. Prepare a "summary" of each LLVM module in question which describes
-///        the values inside, cost of the values, etc.
-///     2. Merge the summaries of all modules in question into one "index"
-///     3. Perform some global analysis on this index
-///     4. For each module, use the index and analysis calculated previously to
-///        perform local transformations on the module, for example inlining
-///        small functions from other modules.
-///     5. Run thin-specific optimization passes over each module, and then code
-///        generate everything at the end.
+///    1. Prepare a "summary" of each LLVM module in question which describes
+///       the values inside, cost of the values, etc.
+///    2. Merge the summaries of all modules in question into one "index"
+///    3. Perform some global analysis on this index
+///    4. For each module, use the index and analysis calculated previously to
+///       perform local transformations on the module, for example inlining
+///       small functions from other modules.
+///    5. Run thin-specific optimization passes over each module, and then code
+///       generate everything at the end.
 ///
 /// The summary for each module is intended to be quite cheap, and the global
 /// index is relatively quite cheap to create as well. As a result, the goal of

compiler/rustc_codegen_llvm/src/debuginfo/doc.md

@@ -27,9 +27,9 @@ The module is thus driven from an outside client with functions like
 Internally the module will try to reuse already created metadata by
 utilizing a cache. The way to get a shared metadata node when needed is
 thus to just call the corresponding function in this module:
-
-    let file_metadata = file_metadata(cx, file);
-
+```ignore (illustrative)
+let file_metadata = file_metadata(cx, file);
+```
 The function will take care of probing the cache for an existing node for
 that exact file path.
 
@@ -63,7 +63,7 @@ struct List {
 
 will generate the following callstack with a naive DFS algorithm:
 
-```
+```ignore (illustrative)
 describe(t = List)
   describe(t = i32)
   describe(t = Option<Box<List>>)