Fix typos and indentation

Author: allanrenucci

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -72,7 +72,7 @@ class Compiler {
          new LiftTry,                // Put try expressions that might execute on non-empty stacks into their own methods
          new HoistSuperArgs,         // Hoist complex arguments of supercalls to enclosing scope
          new ClassOf,                // Expand `Predef.classOf` calls.
-         new CollectNullableFields,  // Collect fields that can be null out after use in lazy initialization
+         new CollectNullableFields,  // Collect fields that can be nulled out after use in lazy initialization
          new RefChecks) ::           // Various checks mostly related to abstract members and overriding
     List(new TryCatchPatterns,       // Compile cases in try/catch
          new PatternMatcher,         // Compile pattern matches

compiler/src/dotty/tools/dotc/transform/CollectNullableFields.scala

@@ -17,17 +17,17 @@ object CollectNullableFields {
   val name = "collectNullableFields"
 }
 
-/** Collect fields that can be null out after use in lazy initialization.
+/** Collect fields that can be nulled out after use in lazy initialization.
  *
  *  This information is used during lazy val transformation to assign null to private
  *  fields that are only used within a lazy val initializer. This is not just an optimization,
  *  but is needed for correctness to prevent memory leaks. E.g.
  *
- *  {{{
+ *  ```scala
  *  class TestByNameLazy(byNameMsg: => String) {
  *    lazy val byLazyValMsg = byNameMsg
  *  }
- *  }}}
+ *  ```
  *
  *  Here `byNameMsg` should be null out once `byLazyValMsg` is
  *  initialised.