[Bug c++/71092] New: internal compiler error: in cxx_eval_call_expression, at cp/constexpr.c:1449; only with -Os

["bugz at 0x83 dot eu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71092

            Bug ID: 71092
           Summary: internal compiler error: in cxx_eval_call_expression,
                    at cp/constexpr.c:1449; only with -Os
           Product: gcc
           Version: 6.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bugz at 0x83 dot eu
  Target Milestone: ---

When compiling the MSP430 debug stack http://www.ti.com/tool/mspds with GCC
6.1.1, I got this error message:

DLL430_v3/src/TI/DLL430/EM/Sequencer/Sequencer430.h: In constructor
âTI::DLL430::Sequencer430::State::State()â:
DLL430_v3/src/TI/DLL430/EM/Sequencer/Sequencer430.h:60:11:   in constexpr
expansion of âstd::shared_ptr<TI::DLL430::ITriggerCondition>()â
DLL430_v3/src/TI/DLL430/EM/Sequencer/Sequencer430.h:60:11: internal compiler
error: in cxx_eval_call_expression, at cp/constexpr.c:1449
   State() { std::fill_n(nextState, NUM_TRANSITIONS, 0); }
           ^
Please submit a full bug report,
with preprocessed source if appropriate.

To reproduce, compile the attached file with
g++ -c prep.cpp  -Os

With optimisation levels different from -Os, the file compiles just fine, as it
does with GCC 5.3.0.

Sorry for not being able to provide a more concise test case, but I haven't yet
been able to isolate the issue.