Qt 5.15.2 doesn't build on Fedora 34

[daleglass]

Probably QTBUG-90395

Creating qmake...
In file included from ../include/QtCore/qfloat16.h:1,
                 from ../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h:44,
                 from ../include/QtCore/qendian.h:1,
                 from /home/dale/Vircadia/qt5/qtbase/src/corelib/codecs/qutfcodec.cpp:43:
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:7: error: ‘numeric_limits’ is not a class template
  300 | class numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> : public numeric_limits<float>
      |       ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:77: error: expected template-name before ‘<’ token
  300 | class numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> : public numeric_limits<float>
      |                                                                             ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:77: error: expected ‘{’ before ‘<’ token
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:344:18: error: ‘numeric_limits’ is not a class template
  344 | template<> class numeric_limits<const QT_PREPEND_NAMESPACE(qfloat16)>
      |                  ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:344:69: error: ‘std::numeric_limits’ is not a template
  344 | template<> class numeric_limits<const QT_PREPEND_NAMESPACE(qfloat16)>
      |                                                                     ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:7: note: previous declaration here
  300 | class numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> : public numeric_limits<float>
      |       ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:345:28: error: expected template-name before ‘<’ token
  345 |     : public numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> {};
      |                            ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:346:18: error: ‘numeric_limits’ is not a class template
  346 | template<> class numeric_limits<volatile QT_PREPEND_NAMESPACE(qfloat16)>
      |                  ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:346:72: error: ‘std::numeric_limits’ is not a template
  346 | template<> class numeric_limits<volatile QT_PREPEND_NAMESPACE(qfloat16)>
      |                                                                        ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:7: note: previous declaration here
  300 | class numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> : public numeric_limits<float>
      |       ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:347:28: error: expected template-name before ‘<’ token
  347 |     : public numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> {};
      |                            ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:348:18: error: ‘numeric_limits’ is not a class template
  348 | template<> class numeric_limits<const volatile QT_PREPEND_NAMESPACE(qfloat16)>
      |                  ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:348:78: error: ‘std::numeric_limits’ is not a template
  348 | template<> class numeric_limits<const volatile QT_PREPEND_NAMESPACE(qfloat16)>
      |                                                                              ^
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:300:7: note: previous declaration here
  300 | class numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> : public numeric_limits<float>
      |       ^~~~~~~~~~~~~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qfloat16.h:349:28: error: expected template-name before ‘<’ token
  349 |     : public numeric_limits<QT_PREPEND_NAMESPACE(qfloat16)> {};
      |                            ^
In file included from ../include/QtCore/qendian.h:1,
                 from /home/dale/Vircadia/qt5/qtbase/src/corelib/codecs/qutfcodec.cpp:43:
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h: In static member function ‘static constexpr QSpecialInteger<S> QSpecialInteger<S>::max()’:
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h:331:30: error: ‘std::numeric_limits’ is not a template
  331 |     { return QSpecialInteger(std::numeric_limits<T>::max()); }
      |                              ^~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h:331:54: error: incomplete type ‘std::numeric_limits’ used in nested name specifier
  331 |     { return QSpecialInteger(std::numeric_limits<T>::max()); }
      |                                                      ^~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h: In static member function ‘static constexpr QSpecialInteger<S> QSpecialInteger<S>::min()’:
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h:333:30: error: ‘std::numeric_limits’ is not a template
  333 |     { return QSpecialInteger(std::numeric_limits<T>::min()); }
      |                              ^~~
../include/QtCore/../../../../qt5/qtbase/src/corelib/global/qendian.h:333:54: error: incomplete type ‘std::numeric_limits’ used in nested name specifier
  333 |     { return QSpecialInteger(std::numeric_limits<T>::min()); }
      |                                                      ^~~