[Bug c++/80465] New: [7 Regression] ICE when evaluating a lamba noexcept spec with captures in C++1z

["eric at efcs dot ca" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80465

            Bug ID: 80465
           Summary: [7 Regression] ICE when evaluating a lamba noexcept
                    spec with captures in C++1z
           Product: gcc
           Version: 7.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: eric at efcs dot ca
  Target Milestone: ---

Reproducer:
// g++ -fsyntax-only -std=c++1z test.cpp
int foo(...);
int main() {
  [](auto a) noexcept(noexcept(foo(a))){}(42);
}

The ICE gives the message: internal compiler error: in nothrow_spec_p, at
cp/except.c:1159

Note that this is a regression and does not occur with GCC 6 with -std=c++1z.