Fix linking ANGLE on MinGW-w64 64-bit

The MinGW-w64 32-bit .def files shouldn't be used with MinGW-w64 64-bit.
Rename .def files from <library>_mingw.def to <library>_mingw32.def and
only use them if QT_ARCH is i386.

Change-Id: I5dc2a87f7d2ed59bf954faf2983d0787ed9e00e9
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Patrick von Reth <vonreth@kde.org>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

src/angle/README.qt

@@ -31,7 +31,7 @@ with the LIBRARY name entry adapted.
 
 MinGW-w64 32-bit requires function exports in the .def files
 to be decorated. Modified versions of the .def files are created as
-<library>_mingw.def. The decorated names of each function can be found
+<library>_mingw32.def. The decorated names of each function can be found
 using the nm command to list the symbols in libEGL.o and libGLESv2.o.
 
 Using a custom ANGLE

src/angle/src/libEGL/libEGL.pro

@@ -26,7 +26,7 @@ SOURCES += \
 
 !static {
     DEF_FILE = $$ANGLE_DIR/src/libEGL/$${TARGET}.def
-    win32-g++*: DEF_FILE = $$ANGLE_DIR/src/libEGL/$${TARGET}_mingw.def
+    win32-g++*:equals(QT_ARCH, i386): DEF_FILE = $$ANGLE_DIR/src/libEGL/$${TARGET}_mingw32.def
 }
 
 load(qt_installs)

src/angle/src/libGLESv2/libGLESv2.pro

@@ -68,7 +68,7 @@ SSE2_SOURCES += $$ANGLE_DIR/src/libGLESv2/TextureSSE2.cpp
 
 !static {
     DEF_FILE = $$ANGLE_DIR/src/libGLESv2/$${TARGET}.def
-    win32-g++*: DEF_FILE = $$ANGLE_DIR/src/libGLESv2/$${TARGET}_mingw.def
+    win32-g++*:equals(QT_ARCH, i386): DEF_FILE = $$ANGLE_DIR/src/libGLESv2/$${TARGET}_mingw32.def
 }
 
 float_converter.target = float_converter