[Issue 22034] New: std.ascii can't be used with -betterc

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22034

          Issue ID: 22034
           Summary: std.ascii can't be used with -betterc
           Product: D
           Version: D2
          Hardware: x86_64
                OS: All
            Status: NEW
          Severity: critical
          Priority: P1
         Component: phobos
          Assignee: nobody at puremagic.com
          Reporter: bitworld at qq.com

Here is a simple code for test:

```
import std.ascii : isLower;

extern(C) void main()
{
    bool r = isLower('A');
}
```

To run:
```
dmd app.d -betterC
```

The error message:

```
app.o: In function `main':
source/app.d:(.text.main[main]+0xa): undefined reference to
`_D3std5ascii7isLowerFNaNbNiNfwZb'
collect2: error: ld returned 1 exit status
Error: linker exited with status 1
```


The compiler is DMD v2.097.0.

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