[Bug c++/101093] New: C++20 Module ICE cannot define 'enum class std::align_val_t' in different module

["unlvsur at live dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101093

            Bug ID: 101093
           Summary: C++20 Module ICE cannot define 'enum class
                    std::align_val_t' in different module
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: unlvsur at live dot com
  Target Milestone: ---

Created attachment 51030
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51030&action=edit
preprocess file

D:\hg\fast_io\src>g++ -c fast_io.cc -fmodules-ts -std=c++20 -s -flto
-march=native -Ofast
In file included from
d:\x86_64-w64-mingw32\include\c++\12.0.0\bits\stl_iterator.h:82,
                 from ../include/fast_io_core_impl/freestanding/iterator.h:6,
                 from ../include/fast_io_core_impl/freestanding/impl.h:12,
                 from ../include/fast_io_core.h:22,
                 from ../include/fast_io_freestanding.h:12,
                 from ../include/fast_io_hosted.h:17,
                 from ../include/fast_io.h:9,
                 from fast_io.cc:6:
d:\x86_64-w64-mingw32\include\c++\12.0.0\new:89:27: error: cannot define 'enum
class std::align_val_t' in different module
   89 |   enum class align_val_t: size_t {};
      |                           ^~~~~~
<built-in>: note: declared here
d:\x86_64-w64-mingw32\include\c++\12.0.0\new:89:27: internal compiler error:
tree check: expected class 'type', have 'exceptional' (error_mark) in
start_enum, at cp/decl.c:15807
libbacktrace could not find executable to open
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.