title: PyQt5 Windows built failure
body: <p>I'm trying to build PyQt5 in Windows 7 using mingw53_32 toolchain taken from 5.9.1. Configure step passed successfully, but got many linking errors while building, here is the end of <code>make</code> output:</p>
  
  <pre><code>C:\Work\PyQt5_gpl-5.9&gt;mingw32-make.exe
  &lt;...&gt;
  ./release\qpycore_qjsonvalue.o:qpycore_qjsonvalue.cpp:(.text+0x45): undefined reference to `_imp__PyBool_Type'
  ./release\qpycore_qjsonvalue.o:qpycore_qjsonvalue.cpp:(.text+0x60): undefined reference to `_imp__PyFloat_Type'
  ./release\qpycore_qjsonvalue.o:qpycore_qjsonvalue.cpp:(.text+0x185): undefined reference to `_imp__PyBool_Type'
  ./release\qpycore_qjsonvalue.o:qpycore_qjsonvalue.cpp:(.text+0x1a8): undefined reference to `_imp__PyFloat_Type'
  ./release\qpycore_qjsonvalue.o:qpycore_qjsonvalue.cpp:(.text+0x434): undefined reference to `_imp___Py_TrueStruct'
  ./release\qpycore_qobject_getattr.o:qpycore_qobject_getattr.cpp:(.text+0x141): undefined reference to `_imp__PyExc_AttributeError'
  ./release\qpycore_qobject_helpers.o:qpycore_qobject_helpers.cpp:(.text+0x5e1): undefined reference to `_imp__PyExc_AttributeError'
  ./release\qpycore_types.o:qpycore_types.cpp:(.text+0xe7c): undefined reference to `_imp__PyExc_TypeError'
  collect2.exe: error: ld returned 1 exit status
  Makefile.Release:893: recipe for target 'release\QtCore.dll' failed
  mingw32-make.exe[2]: *** [release\QtCore.dll] Error 1
  mingw32-make.exe[2]: Leaving directory 'C:/Work/PyQt5_gpl-5.9/QtCore'
  Makefile:36: recipe for target 'release' failed
  mingw32-make.exe[1]: *** [release] Error 2
  mingw32-make.exe[1]: Leaving directory 'C:/Work/PyQt5_gpl-5.9/QtCore'
  Makefile:76: recipe for target 'sub-QtCore-make_first-ordered' failed
  mingw32-make.exe: *** [sub-QtCore-make_first-ordered] Error 2
  </code></pre>
  
  <p>Could anybody suggest me how to fix these errors?</p>