Fix the build by removing a not-yet needed method

pkg/analyzer/lib/src/generated/source.dart

Index: pkg/analyzer/lib/src/generated/source.dart
diff --git a/pkg/analyzer/lib/src/generated/source.dart b/pkg/analyzer/lib/src/generated/source.dart
index 850846810b7e16d1a8138144706a3c58687bc684..24fec623ea748adab62aba90c34383d566fd6c2a 100644
--- a/pkg/analyzer/lib/src/generated/source.dart
+++ b/pkg/analyzer/lib/src/generated/source.dart
@@ -208,16 +208,16 @@ class LineInfo {
     }
   }
 
-  /**
-   * Return the offset of the first character on the line with the given
-   * [lineNumber].
-   */
-  int getLineOffset(int lineNumber) {
-    if (lineNumber < 0 || lineNumber >= _lineStarts.length) {
-      throw new ArgumentError('Invalid line number: $lineNumber');
-    }
-    return _lineStarts[lineNumber];
-  }
+//  /**
+//   * Return the offset of the first character on the line with the given
+//   * [lineNumber].
+//   */
+//  int getLineOffset(int lineNumber) {
+//    if (lineNumber < 0 || lineNumber >= _lineStarts.length) {
+//      throw new ArgumentError('Invalid line number: $lineNumber');
+//    }
+//    return _lineStarts[lineNumber];
+//  }
 
   /**
    * Return the location information for the character at the given offset.