Unicode support for Collection>>split:

[dram]

Describe the bug

Unicode support for Collection>>split: is broken, it will cause IntraCharacterInde error.

To Reproduce

Try following code to reproduce:

#($一 $二 $三) split: '1一2二3三'

Additional context

Following is full backtrace:

Utf8String(Object)>>error:
Utf8String(UtfEncodedString)>>errorIntraCharacterIndex:
Utf8String>>decodeAt:
Utf8String(UtfEncodedString)>>uncheckedFrom:to:keysAndValuesDo:
Utf8String(SequenceableCollection)>>from:to:keysAndValuesDo:
Utf8String(SequenceableCollection)>>from:keysAndValuesDo:
Array(Collection)>>_indexOfAnyInString:startingAt:
Utf8String(String)>>indexOfAnyOf:startingAt:
Array(Collection)>>split:
...