armv7 compilation of source fails due to instructions only available with armv7s

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -c -Xarch_armv7 -include.pch/Qt5Core/c++_armv7 -Xarch_arm64 -include.pch/Qt5Core/c++_arm64 -Xarch_x86_64 -include.pch/Qt5Core/c++_x86_64 -pipe -stdlib=libc++ -O3 -fPIC -std=c++1y -fapplication-extension  -arch armv7  -arch arm64  -arch x86_64 -Xarch_armv7 -miphoneos-version-min=10.0 -Xarch_armv7 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk -Xarch_arm64 -miphoneos-version-min=10.0 -Xarch_arm64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk -Xarch_x86_64 -mios-simulator-version-min=10.0 -Xarch_x86_64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.3.sdk -fobjc-nonfragile-abi -fobjc-legacy-dispatch -fvisibility=hidden -fvisibility-inlines-hidden -fembed-bitcode -Wall -W -Werror=unguarded-availability -Werror=unguarded-availability-new -Werror=unsupported-availability-guard -DQT_COMPILER_SUPPORTS_SSE2 -DQT_NO_USING_NAMESPACE -DQT_NO_FOREACH -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_BUILD_CORE_LIB -DQT_BUILDING_QT -DQT_NO_CAST_TO_ASCII -DQT_ASCII_CAST_WARNINGS -DQT_MOC_COMPAT -DQT_USE_QSTRINGBUILDER -DQT_DEPRECATED_WARNINGS -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DPCRE2_CODE_UNIT_WIDTH=16 -I. -I../../mkspecs/common/uikit -Iglobal -I../3rdparty/harfbuzz/src -I../3rdparty/md5 -I../3rdparty/md4 -I../3rdparty/sha3 -I../3rdparty/double-conversion/include -I../3rdparty/double-conversion/include/double-conversion -I../../include -I../../include/QtCore -I../../include/QtCore/5.11.0 -I../../include/QtCore/5.11.0/QtCore -I.moc -I.tracegen -I../3rdparty/pcre2/src -I../../mkspecs/macx-ios-clang -o .obj/qfloat16.o global/qfloat16.cpp
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -c -Xarch_armv7 -include.pch/Qt5Core/c++_armv7 -Xarch_arm64 -include.pch/Qt5Core/c++_arm64 -Xarch_x86_64 -include.pch/Qt5Core/c++_x86_64 -pipe -stdlib=libc++ -O3 -fPIC -std=c++1y -fapplication-extension  -arch armv7  -arch arm64  -arch x86_64 -Xarch_armv7 -miphoneos-version-min=10.0 -Xarch_armv7 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk -Xarch_arm64 -miphoneos-version-min=10.0 -Xarch_arm64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk -Xarch_x86_64 -mios-simulator-version-min=10.0 -Xarch_x86_64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.3.sdk -fobjc-nonfragile-abi -fobjc-legacy-dispatch -fvisibility=hidden -fvisibility-inlines-hidden -fembed-bitcode -Wall -W -Werror=unguarded-availability -Werror=unguarded-availability-new -Werror=unsupported-availability-guard -DQT_COMPILER_SUPPORTS_SSE2 -DQT_NO_USING_NAMESPACE -DQT_NO_FOREACH -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_BUILD_CORE_LIB -DQT_BUILDING_QT -DQT_NO_CAST_TO_ASCII -DQT_ASCII_CAST_WARNINGS -DQT_MOC_COMPAT -DQT_USE_QSTRINGBUILDER -DQT_DEPRECATED_WARNINGS -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DPCRE2_CODE_UNIT_WIDTH=16 -I. -I../../mkspecs/common/uikit -Iglobal -I../3rdparty/harfbuzz/src -I../3rdparty/md5 -I../3rdparty/md4 -I../3rdparty/sha3 -I../3rdparty/double-conversion/include -I../3rdparty/double-conversion/include/double-conversion -I../../include -I../../include/QtCore -I../../include/QtCore/5.11.0 -I../../include/QtCore/5.11.0/QtCore -I.moc -I.tracegen -I../3rdparty/pcre2/src -I../../mkspecs/macx-ios-clang -o .obj/qoperatingsystemversion.o global/qoperatingsystemversion.cpp
global/qfloat16.cpp:149:31: error: use of undeclared identifier 'vcvt_f16_f32'
        vst1_f16(out_f16 + i, vcvt_f16_f32(vld1q_f32(in + i)));
                              ^
global/qfloat16.cpp:159:28: error: use of undeclared identifier 'vcvt_f32_f16'
        vst1q_f32(out + i, vcvt_f32_f16(vld1_f16(in_f16 + i)));
                           ^
2 errors generated.
make[3]: *** [.obj/qfloat16.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [sub-corelib-make_first] Error 2
make[1]: *** [sub-src-make_first] Error 2
make: *** [module-qtbase-make_first] Error 2