[Bug c++/118445] New: VEC_DUPLICATE_EXPR not handled by potential_constant_expression_1

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118445

            Bug ID: 118445
           Summary: VEC_DUPLICATE_EXPR not handled by
                    potential_constant_expression_1
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Split out from PR 118377.
Take:
```
#include <arm_sve.h>

constexpr svfloat32_t f(svfloat32_t b, float a)
{
  return b + a;
}
```