@forceInline can't inline when source code is available

[Mike via D.gnu]

Consider this code

testInline.d
************
module testInline;

import gcc.attribute;

public enum inline = gcc.attribute.attribute("forceinline");

@inline int add(int a, int b)
{
     return a + b;
}

test.d
******
import std.stdio;

import testInline;

void main()
{
     writeln(add(1, 2));
}

Compiler Output
***************
gdc test.d
test.d: In function 'D main':
testInline.d:7:13: error: inlining failed in call to 
always_inline 'add': function body not available
  @inline int add(int a, int b)
              ^
test.d:8:5: error: called from here
      writeln(add(1, 2));
      ^


Shouldn't it be able to inline the "add" function since the 
source code is there in the testInline.d file?  Should I file a 
bug?

Mike