[gardening] Remove done TODO comments

Author: milseman

stdlib/public/core/StringCharacterView.swift

@@ -315,7 +315,6 @@ extension String.CharacterView : BidirectionalCollection {
       // others:
       //   0x3400-0xA4CF
       case 0x3400...0xa4cf: return true
-      // TODO: CJK punctuation
 
       // Repeat sub-300 check, this is beneficial for common cases of Latin
       // characters embedded within non-Latin script (e.g. newlines, spaces,
@@ -324,8 +323,6 @@ extension String.CharacterView : BidirectionalCollection {
       // NOTE: CR-LF special case has already been checked.
       case 0x0000...0x02ff: return true
 
-      // TODO: general punctuation
-
       // Non-combining kana:
       //   0x3041-0x3096
       //   0x30A1-0x30FA