Dart SDK Spelling b, c, and d.

pkg/compiler/lib/src/io/position_information.dart

Index: pkg/compiler/lib/src/io/position_information.dart
diff --git a/pkg/compiler/lib/src/io/position_information.dart b/pkg/compiler/lib/src/io/position_information.dart
index d6889d71dc0492dc32bee91d7014af1f73d621c5..0c94faa51f68dd0cb6447d8b03a84e63282ed5cb 100644
--- a/pkg/compiler/lib/src/io/position_information.dart
+++ b/pkg/compiler/lib/src/io/position_information.dart
@@ -694,7 +694,7 @@ class Offset {
   final int subexpressionOffset;
 
   /// The `left-to-right` offset of the step. This is like [subexpressionOffset]
-  /// bute restricted so that the offset of each subexpression in execution
+  /// but restricted so that the offset of each subexpression in execution
   /// order is monotonically increasing.
   ///
   /// For instance: