6868 – IsExp + incorrect static array type = error

Code:
----
@property bool empty(T)(in T[] a) @safe pure nothrow
{
 return !a.length;
}
void main()
{
 alias int[] Range;
 static if (is(char[1 + Range.empty])) // Line 9
 enum bool isInfinite = true;
 char[0] s; // need
}
Output:
----
test.d(9): Error: Integer constant expression expected instead of cast(uint)(1 + cast(int)empty((__error)))

Original code:
----
import std.range;
void main()
{
 pragma(msg, isInfinite!(int[]));
 char[0] s; // need
}

https://github.com/D-Programming-Language/dmd/pull/482
And change importance: normal -> major
In my opinion, this issue is important, because std.range.isInfinite is used frequently.

https://github.com/D-Programming-Language/dmd/commit/de0368bdad0df70122a055284ddc55fbf22f4be7
https://github.com/D-Programming-Language/dmd/commit/02dff8cf67356ca36cbb363c36665073a96e2099