Try to reproduce ubsan issue #8525

Job	Run time
stage1 (frozen-cxx03-headers, clang-19, clang++-19)	9m 3s
stage1 (generic-cxx03, clang-19, clang++-19)	8m 40s
stage1 (generic-cxx26, clang-19, clang++-19)	13m 51s
stage1 (generic-modules, clang-19, clang++-19)	9m 37s
stage1 (generic-gcc, gcc-14, g++-14)	19m 37s
windows (clang-cl-dll, false)	52m 12s
macos (generic-cxx03, macos-15)	12m 4s
stage2 (generic-cxx11, clang-19, clang++-19)	10m 1s
windows (clang-cl-static, false)	52m 36s
stage2 (generic-cxx14, clang-19, clang++-19)	9m 56s
windows (clang-cl-no-vcruntime, false)	51m 45s
stage2 (generic-cxx17, clang-19, clang++-19)	12m 21s
macos (generic-cxx23, macos-15)	26m 39s
stage2 (generic-cxx20, clang-19, clang++-19)	19m 24s
macos (generic-modules, macos-15)	22m 0s
windows (clang-cl-debug, false)	50m 52s
macos (apple-configuration, macos-15)	38m 48s
stage2 (generic-cxx23, clang-19, clang++-19)	11m 10s
macos (apple-system, macos-13)	1h 9m 58s
windows (clang-cl-static-crt, false)	54m 38s
stage2 (generic-gcc-cxx11, gcc-14, g++-14)	11m 4s
macos (apple-system-hardened, macos-13)	1h 8m 3s
windows (mingw-dll, true)	1h 9m 50s
stage2 (generic-cxx23, clang-17, clang++-17)	13m 45s
windows (mingw-static, true)	1h 10m 21s
stage2 (generic-cxx26, clang-18, clang++-18)	12m 35s
windows (mingw-dll-i686, true)	1h 11m 11s
windows (mingw-incomplete-sysroot, true)	6m 37s
stage3	0s
	14h 38m 38s

Provide feedback