Known immutable named expression/variable not being accepted when it should be.
Version: DMD32 D Compiler v2.063.2
enum len = 4;
alias e1 = immutable(char)[len];
alias e2 = immutable(char[len]); //fails, line 9
alias immutable(char)[len] e3;
alias immutable(char[len]) e4; //fails, line 11
immutable ilen = 4;
alias i1 = immutable(char)[ilen];
alias i2 = immutable(char[ilen]); //fails, line 15
alias immutable(char)[ilen] i3;
alias immutable(char[ilen]) i4; //fails, line 17
test.d(9): Error: Integer constant expression expected instead of len
test.d(11): Error: Integer constant expression expected instead of len
test.d(15): Error: Integer constant expression expected instead of ilen
test.d(17): Error: Integer constant expression expected instead of ilen