Crash with `en-u-nu-latn` locale

Originator:artyom.stv
Number:rdar://48139453 Date Originated:16.02.2019
Status:Open Resolved:
Product:iOS SDK Product Version:12.1
Classification:Crash Reproducible:Always
 
Summary:
`-[NSString initWithFormat:locale:]` crashes on attempt to format `%lu`with `en-u-nu-latn` locale

Steps to Reproduce:
Run code:
```
NSLocale *locale = [NSLocale localeWithLocaleIdentifier:@"en-u-nu-latn"];
NSString *string = [[NSString alloc] initWithFormat:@"%lu" locale:locale, 123lu];
```

Expected Results:
`NSString` initializer doesn't crash

Actual Results:
`NSString` initializer crashes
Error:
```
Thread 1: EXC_BAD_ACCESS (code=1, address=0x20)
```
Call stack:
```
#0	0x000000018f163734 in CFNumberFormatterGetFormat ()
#1	0x000000018f19eee0 in __CFStringAppendFormatCore ()
#2	0x000000018f19fdf0 in _CFStringCreateWithFormatAndArgumentsAux2 ()
#3	0x000000018fb8e1dc in -[NSString initWithFormat:locale:] ()
```

Comments


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