[Bug c++/66517] New: [5 Regression] [C++11] sorry, unimplemented: unexpected AST of kind type_decl

[megahallon at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66517

            Bug ID: 66517
           Summary: [5 Regression] [C++11] sorry, unimplemented:
                    unexpected AST of kind type_decl
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: megahallon at gmail dot com
  Target Milestone: ---

The following snippet:

-------------------------------------
template <typename S>
void p()
{
  int val = ({union {int x;}; 3;}
  );
}
-------------------------------------

built with g++ 5.1.0:

g++ -std=c++11 bug.cpp -c

gives the following error:

bug.cpp: In function ‘void p()’:
bug.cpp:5:3: sorry, unimplemented: unexpected AST of kind type_decl
   );
   ^

Same error with -std=c++14 but works with -std=c++98.
Also works with g++ 4.8.2.

Output from g++ -v:

Using built-in specs.
COLLECT_GCC=/usr/local/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/5.1.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ./configure --prefix=/usr/local --enable-languages=c,c++
--disable-multilib
Thread model: posix
gcc version 5.1.0 (GCC)