1571 – Segfault(class.c) const on function parameters not carried through to .di file

class C;
void foo(const C c);
and compiling with -H gives a .di file that is missing the const.

This now segfaults. crashing ClassDeclaration::toCBuffer on members->dim when members is null.
With the attached patch, as well as preventing the crash, the correct output is produced.
Patch: class.c line 735 and 749. should ensure class has members,
before writing the members out!
+if(members){
	buf->writenl();
	buf->writeByte('{');
		buf->writenl();
	for (int i = 0; i < members->dim; i++)
	{
	 Dsymbol *s = (Dsymbol *)members->data[i];
	 buf->writestring(" ");
	 s->toCBuffer(buf, hgs);
 }
 buf->writestring("}");
 + } else	buf->writestring(";");

Fixed dmd 1.048 and 2.033