IE8: can't delete whole text before an anchor.

[Jakub Ś]

1. Open replacebycode sample
2. Insert anchor "This is some sample text. Yo^{u are using CKEditor." inside "You" word}
3. Move the cursor to the beginning of line
4. Start deleting text with DELETE

Result:
When you reach "o" in "You" word and press DELETE "o" will be deleted with anchor.

Reproducible from CKE 3.6 rev [6904] in IE8