fix issue 11052 - pathSplitter cannot be converted to string[], and to!() fails

[ghost]

to now works on pathSplitterresult using the cast operator overloading. Since the function returns a lazy range there's very little chances that anyone ever used cast on it (which would stop working with this change).

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	11052	normal	pathSplitter cannot be converted to string[], and to!() template fails

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub fetch digger
dub run digger -- build "master + phobos#6679"

[ghost]

Actually this is more an enhancement; to has no overload that converts input ranges to arrays.

[ghost]

This is useless actually.