[r17-1353 Regression] FAIL: g++.dg/warn/Warray-bounds15.C -std=gnu++26 (test for warnings, line 38) on Linux/x86_64

On Linux/x86_64,

106970adca69c9c577e6c75f4e69a08cd9ea2df0 is the first bad commit
commit 106970adca69c9c577e6c75f4e69a08cd9ea2df0
Author: Martin Uecker <[email protected]>
Date:   Wed Jun 3 17:57:30 2026 +0200

    c: harmonize handling of arrays

caused

FAIL: gcc.dg/debug/ctf/ctf-array-2.c scan-assembler-times 0x12000000[\t ]+[^\n]*ctt_info 2
FAIL: gcc.dg/debug/ctf/ctf-array-2.c scan-assembler-times [\t ]0[\t ]+[^\n]*cta_nelems 2
FAIL: gcc.dg/Warray-bounds-52.c (test for excess errors)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 19)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 20)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 21)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 34)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 35)
FAIL: gcc.dg/Warray-bounds-53.c (test for excess errors)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 19)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 20)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 21)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 34)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 35)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++14  (test for warnings, line 38)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++20  (test for warnings, line 38)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++26  (test for warnings, line 38)

with GCC configured with

../../gcc/configure --prefix=/export/users3/haochenj/src/gcc-bisect/master/master/r17-1353/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap

To reproduce:

$ cd {build_dir}/gcc && make check RUNTESTFLAGS="ctf.exp=gcc.dg/debug/ctf/ctf-array-2.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="ctf.exp=gcc.dg/debug/ctf/ctf-array-2.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-52.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-52.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-53.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-53.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=g++.dg/warn/Warray-bounds15.C --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="dg.exp=g++.dg/warn/Warray-bounds15.C --target_board='unix{-m32\ -march=cascadelake}'"

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