sample code:
module test.d;

void foo()
{
}

void main()
{
    foo();
}

$ dmd -v -g -c debug-names.d  (or -gc instead of -g, same results)
$ objdump --syms debug-names.o

debug-names.o:     file format elf32-i386

SYMBOL TABLE: (output edited to hide parts not relevant)
00000000 l    df *ABS*  00000000 debug-names.d
00000000 l    d  .text._D4test1d3fooFZv 00000000 .text._D4test1d3fooFZv
00000000 g     F .text._D4test1d3fooFZv 00000005 _D4test1d3fooFZv

secondary evidence (gdb from cvs with the recent patches to support d):

(gdb) list test.d.foo
1  module test.d;
2
3  void foo()
4  {
5  }
6
7  void main()
8  {
9      foo();
10 }
(gdb) list test.foo
Can't find member of namespace, class, struct, or union named "test.foo"
Hint: try 'test.foo<TAB> or 'test.foo<ESC-?>
(Note leading single quote.)