Qt fails to build on certain Intel CPUs due to avx512_fp16 with GCC14 (src/gui/painting/qrgbafloat.h)

[...]
FAILED: src/gui/CMakeFiles/Gui.dir/image/qimage.cpp.o  
/usr/bin/x86_64-pc-linux-gnu-c++ -DENABLE_PIXMAN_DRAWHELPERS -DGui_EXPORTS -DQT_ASCII_CAST_WARNINGS -DQT_BUILDING_QT -DQT_BUILD_GUI_LIB -DQT_CORE_LIB -DQT_DBUS_LIB -DQT_DEPRECATED_WARNINGS -DQT_EXPLICIT_QFILE_CONSTRUCTION_FROM_PATH -DQT
_LEAN_HEADERS=1 -DQT_MOC_COMPAT -DQT_NO_CAST_TO_ASCII -DQT_NO_CONTEXTLESS_CONNECT -DQT_NO_DEBUG -DQT_NO_EXCEPTIONS -DQT_NO_FOREACH -DQT_NO_JAVA_STYLE_ITERATORS -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_QASCONST -DQT_NO_QEXCHANGE 
-DQT_NO_QSNPRINTF -DQT_NO_USING_NAMESPACE -DQT_QPA_DEFAULT_PLATFORM_NAME=\"xcb\" -DQT_USE_NODISCARD_FILE_OPEN -DQT_USE_QSTRINGBUILDER -D_GLIBCXX_ASSERTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I/var/tmp/paludis/build/x11-libs-qtba
se-6.8.2/work/build/src/gui/Gui_autogen/include -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtGui -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/wor
k/qtbase-everywhere-src-6.8.2/src/gui -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/src/gui -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/../3rdparty/VulkanMemoryAllocator -I/var/tmp
/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/../3rdparty/D3D12MemoryAllocator -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtGui/6.8.2 -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/
work/build/include/QtGui/6.8.2/QtGui -I/usr/x86_64-pc-linux-gnu/include/at-spi-2.0 -I/usr/x86_64-pc-linux-gnu/include/dbus-1.0 -I/usr/x86_64-pc-linux-gnu/lib/dbus-1.0/include -I/usr/x86_64-pc-linux-gnu/include/libmount -I/usr/x86_64-pc-
linux-gnu/include/uuid -I/usr/x86_64-pc-linux-gnu/include/json-c -I/usr/x86_64-pc-linux-gnu/lib/openssl-3/include -I/usr/x86_64-pc-linux-gnu/include/blkid -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtCore -I/var/t
mp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/mkspecs/linux-g++ -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/src/corelib -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtCore/6.8
.2 -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtCore/6.8.2/QtCore -I/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtDBus -isystem /usr/x86_64-pc-linux-gnu/include/glib-2.0 -isystem /usr/x86_64-pc
-linux-gnu/lib/glib-2.0/include -isystem /usr/x86_64-pc-linux-gnu/include/harfbuzz -isystem /usr/x86_64-pc-linux-gnu/include/freetype2 -isystem /usr/x86_64-pc-linux-gnu/include/libpng16 -march=native -O2 -pipe -std=gnu++17 -fPIC -fvisib
ility=hidden -fvisibility-inlines-hidden -fdiagnostics-color=always -Wall -Wextra -fno-exceptions -mno-direct-extern-access -U_FORTIFY_SOURCE -Wsuggest-override -fcf-protection=full -D_FORTIFY_SOURCE=3 -ftrivial-auto-var-init=pattern -f
stack-protector-strong -fstack-clash-protection -Winvalid-pch -include /var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/src/gui/CMakeFiles/Gui.dir/cmake_pch.hxx -MD -MT src/gui/CMakeFiles/Gui.dir/image/qimage.cpp.o -MF src/gui/CM
akeFiles/Gui.dir/image/qimage.cpp.o.d -o src/gui/CMakeFiles/Gui.dir/image/qimage.cpp.o -c /var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/image/qimage.cpp 
In file included from /var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/build/include/QtGui/qrgbafloat.h:1, 
                from /var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/image/qimage.cpp:14: 
/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/painting/qrgbafloat.h: In instantiation of 'constexpr QRgbaFloat<T> QRgbaFloat<T>::unpremultiplied() const [with F = qfloat16]': 
/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/image/qimage.cpp:2737:34:   required from here 
2737 |             p = p.unpremultiplied(); 
     |                 ~~~~~~~~~~~~~~~~~^~ 
/var/tmp/paludis/build/x11-libs-qtbase-6.8.2/work/qtbase-everywhere-src-6.8.2/src/gui/painting/qrgbafloat.h:102:34: error: conversion from 'float' to non-scalar type 'const QRgbaFloat<qfloat16>::FastType' {aka 'const qfloat16'} requeste
d 
 102 |         const FastType ia = 1.0f / a; 
     |                             ~~~~~^~~ 
ninja: build stopped: subcommand failed.

processor       : 0 
vendor_id       : GenuineIntel 
cpu family      : 6 
model           : 143 
model name      : Intel(R) Xeon(R) Gold 6442Y 
stepping        : 6 
microcode       : 0x2b000590 
cpu MHz         : 2599.999 
cache size      : 61440 KB 
physical id     : 0 
siblings        : 8 
core id         : 0 
cpu cores       : 8 
apicid          : 0 
initial apicid  : 0 
fpu             : yes 
fpu_exception   : yes 
cpuid level     : 32 
wp              : yes 
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology tsc_reliable nonstop_tsc cpuid tsc_
known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch ssbd ibrs ibpb stibp ibrs_enhanced fsgsbase tsc_adjust bmi1 avx2 smep bmi2 
erms invpcid avx512f avx512dq rdseed adx smap avx512ifma clflushopt clwb avx512cd sha_ni avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves avx_vnni avx512_bf16 wbnoinvd arat avx512vbmi umip pku ospke avx512_vbmi2 gfni vaes vpclmulqdq avx
512_vnni avx512_bitalg avx512_vpopcntdq rdpid cldemote movdiri movdir64b fsrm md_clear serialize amx_bf16 avx512_fp16 amx_tile amx_int8 flush_l1d arch_capabilities 
bugs            : spectre_v1 spectre_v2 spec_store_bypass swapgs itlb_multihit mmio_unknown eibrs_pbrsb bhi 
bogomips        : 5199.99 
clflush size    : 64 
cache_alignment : 64 
address sizes   : 45 bits physical, 48 bits virtual 
power management:

--- a/src/gui/painting/qrgbafloat.h
+++ b/src/gui/painting/qrgbafloat.h
@@ -20,5 +20,5 @@
 public:
     using Type = F;
-#if defined(__AVX512FP16__) && QFLOAT16_IS_NATIVE
+#if 0
     // AVX512FP16 has multiplication instructions
     using FastType = F;