[Bug c++/84801] New: ICE: Segmentation fault instead of "error: parameter packs not expanded with '...'"

[gjl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84801

            Bug ID: 84801
           Summary: ICE: Segmentation fault instead of "error: parameter
                    packs not expanded with '...'"
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gjl at gcc dot gnu.org
  Target Milestone: ---

int v;
int main() { [](auto... c) { v = c; }(1); }

triggers ICE with v8:

$ avr-g++ foo.cpp -std=gnu++14 -v
foo.cpp: In instantiation of 'main()::<lambda(auto:1 ...)> [with auto:1 =
{int}]':
foo.cpp:2:40:   required from here
foo.cpp:2:32: internal compiler error: Segmentation fault
 int main() { [](auto... c) { v = c; }(1); }
                              ~~^~~

Configured with: ../../gcc.gnu.org/trunk/configure --target=avr --disable-nls
--prefix=/gnu/gcc-avr --host=i686-w64-mingw32 --build=x86_64-linux-gnu
--enable-languages=c,c++,lto --with-gnu-as --with-gnu-ld --disable-shared
--with-dwarf2 --enable-checking=release
Thread model: single
gcc version 8.0.1 20180119 (experimental) [trunk revision 256890] (GCC) 

GNU C++14 (GCC) version 8.0.1 20180119 (experimental) [trunk revision 256890]
(avr)
        compiled by GNU C version 4.9.3, GMP version 6.1.0, MPFR version 3.1.4,
MPC version 1.0.3, isl version isl-0.16.1-GMP

v7 issues an error instead:

foo.cpp: In lambda function:
foo.cpp:2:32: error: parameter packs not expanded with '...':
 int main() { [](auto... c) { v = c; }(1); }
                              ~~^~~
foo.cpp:2:32: note:         'c'