Keep the macro "complex" in C++03

[Benjamin De Kosnik]

> Patch is Ok, thanks. You may want to remove the test variable: it
> serves no purpose in a dg-do compile testcase with no VERIFYs in it.

OT, but I cannot resist.

Continued use of VERIFY is VERY inane.

1) static_assert in C++11 is much better for do-compile

2) just throwing an exception with details that are automagically
logged via verbose_terminate is much better for do-run

I've switched over to these two mechanisms. 

-benjamin