message: Rename boxed -> clamped, move comment
diff: @@ -2794,10 +2794,10 @@ class IncrementalTextDocument implements TextDocument {
  throw new Error(`FullPieceTreeTextDocument#update called with invalid event range ${range}`);
  }
  - // Delete previous text at range and insert new text at appropriate offset
  const startOffset = this.offsetAt(range.start);
  const endOffset = this.offsetAt(range.end);
  + // Delete previous text at range and insert new text at appropriate offset
  this._tree.delete(startOffset, endOffset - startOffset);
  this._tree.insert(startOffset, text);
  @@ -2805,8 +2805,8 @@ class IncrementalTextDocument implements TextDocument {
  }
  public positionAt(offset: number) {
  - const boxedOffset = Math.min(offset, this._tree.getLength());
  - const ptPosition: PieceTreePosition = this._tree.getPositionAt(boxedOffset);
  + const clampedOffset = Math.min(offset, this._tree.getLength());
  + const ptPosition: PieceTreePosition = this._tree.getPositionAt(clampedOffset);
  return Position.create(ptPosition.lineNumber - 1, ptPosition.column - 1);
  }
  