No "Unreachable code" warning on a static falsy conditional expression

FPC from trunk

program project1;
var
  a: byte;
begin
  if 1 > 2 then
    a := 0;         // <= no warning
  if False then
    a := 0;         // <= project1.lpr(8,5) Warning: Unreachable code
  Writeln(a);
end.