Strange behaviour with "shared" function parameters

[Maor Ben Dayan via D.gnu]

The following program demonstrates a difference between how gdc & 
dmd handle function parameters qualified as shared:

import std.stdio;
void foo(out shared int x) {
  x = 5;
}

void main()
{
  version (works) {
    shared int b = 4;
  } else {
    int b = 4;
  }
  writeln(b);
  foo(b);
  writeln(b);
}

while both 'dmd ./test.d -of/tmp/a.out' and 'dmd -version=works 
./test.d -of/tmp/a.out' output:
4
5

'gdc -fversion=works ./test.d -o /tmp/a.out' prints the right 
output:
4
5

BUT 'gdc ./test.d -o /tmp/a.out' prints:
4
4

I assume this is a bug, right ?

Maor