[Bug bootstrap/103305] New: [12 Regression] Cannot build aarch64-none-elf

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103305

            Bug ID: 103305
           Summary: [12 Regression] Cannot build aarch64-none-elf
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: build, wrong-code
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tnfchris at gcc dot gnu.org
  Target Milestone: ---
              Host: aarch64-none-linux-gnu
            Target: aarch64-none-elf
             Build: aarch64-none-elf

aarch64-none-elf stage2 cross builds which use newlib fail with:

/build-agent/temp/buildTmp/gcc-2/aarch64-none-elf/libstdc++-v3/include/aarch64-none-elf/bits/ctype_base.h:44:35:
error: '_U' was not declared in this scope
   44 |     static const mask upper     = _U;
      |                                   ^~
/build-agent/temp/buildTmp/gcc-2/aarch64-none-elf/libstdc++-v3/include/aarch64-none-elf/bits/ctype_base.h:45:35:
error: '_L' was not declared in this scope
   45 |     static const mask lower     = _L;
      |                                   ^~
/build-agent/temp/buildTmp/gcc-2/aarch64-none-elf/libstdc++-v3/include/aarch64-none-elf/bits/ctype_base.h:46:35:
error: '_U' was not declared in this scope
   46 |     static const mask alpha     = _U | _L;

and so on.

This looks like the exact same bug as PR103226 but have been asked to make a
new ticket.