Fixed DStress tests nocompile/c/{const_32_B.d,const_32_C.d}. Updated the runtest script to build libtangobos-partial.a if it hasn't already been built. Added in signbit() and va_arg!()() to libtangobos-partial.a so more of the phobos dependent DStress tests pass.

template toInt(char[4] arg)
{
	const uint toInt = (cast(uint[]) arg)[0];
	}
	 
	 void main()
	 {
	   auto i = toInt!("abcd");
	   }