c++: Remove dg-ice in constexpr-52830.C [PR52830]

It turned out that r11-5942 fixed this old PR, and it was detected
by one of the few dg-ice tests -- exactly the point of them!  Now
the PR won't be opened until someone notices that it'd been fixed.
The patch failed to remove the dg-ice though, so now it XPASSes.  Fixing
this now.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/constexpr-52830.C: Remove dg-ice.

gcc/testsuite/g++.dg/cpp0x/constexpr-52830.C

@@ -1,6 +1,5 @@
 // PR c++/52830
 // { dg-do compile { target c++11 } }
-// { dg-ice "comptypes" }
 
 template<bool b> struct eif { typedef void type; };
 template<>       struct eif<false> {};