To reproduce:
1. Open project
2. Play 'Scene1' in the editor or Mac Standalone
3. Copy any of the emojis from the list below the repro steps
4. Paste the emoji in the InputField, ArgumentOutOfRangeException will be thrown
5. Notice that you cannot write to InputField anymore, until standalone build or scene play in editor will be restarted

Reproduced: 5.6.5p2, 2017.1.4f1, 2017.2.3p1, 2017.3.2f1, 2017.4.6f1, 2018.1.6f1, 2018.2.0b9, 2018.3.0a2

Emojis that causes the issue:
List: https://unicode.org/emoji/charts/full-emoji-list.html
- U+1F469 U+200D U+1F467 (Nº 359 from the list) ?
- U+1F469 U+200D U+1F466 (Nº 357 from the list) ?
- U+1F468 U+200D U+1F466 (Nº 352 from the list) ?