build: Fix mingw pkgconfig file and dependency naming

This change adds the correct suffix to debug mode .pc filenames for
MinGW and also to the Qt libraries listed in the `Requires` field.
The filename adjustment fixes the accidental overwriting of release
mode .pc files with the debug mode variant which required the wrong
variant of the libraries when `debug_and_release` is active.
Note that macOS also supports the `debug_and_release' configuration
but may use the regular library names together with DYLD_IMAGE_SUFFIX.
Creation of *_debug.pc files is turned off as they're identical to their
non-debug counterparts.
More info:
- QTBUG-4155
- Qt commit a0d8fb4ac3cb7bafdb39f340055eacee4f957513

depends/patches/qt/fix_qt_pkgconfig.patch

@@ -1,11 +1,23 @@
 --- old/qtbase/mkspecs/features/qt_module.prf
 +++ new/qtbase/mkspecs/features/qt_module.prf
-@@ -245,7 +245,7 @@
+@@ -264,7 +264,7 @@
  load(qt_targets)
  
  # this builds on top of qt_common
 -!internal_module:!lib_bundle:if(unix|mingw) {
-+unix|mingw {
++if(unix|mingw):!if(darwin:debug_and_release:CONFIG(debug, debug|release)) {
      CONFIG += create_pc
      QMAKE_PKGCONFIG_DESTDIR = pkgconfig
      host_build: \
+@@ -274,9 +274,9 @@
+     QMAKE_PKGCONFIG_INCDIR = $$[QT_INSTALL_HEADERS/raw]
+     QMAKE_PKGCONFIG_CFLAGS = -I${includedir}/$$MODULE_INCNAME
+     QMAKE_PKGCONFIG_NAME = $$replace(TARGET, ^Qt, "Qt$$QT_MAJOR_VERSION ")
+-    QMAKE_PKGCONFIG_FILE = $$replace(TARGET, ^Qt, Qt$$QT_MAJOR_VERSION)
++    QMAKE_PKGCONFIG_FILE = $$replace(TARGET, ^Qt, Qt$$QT_MAJOR_VERSION)$$qtPlatformTargetSuffix()
+     for(i, MODULE_DEPENDS): \
+-        QMAKE_PKGCONFIG_REQUIRES += $$replace(QT.$${i}.name, ^Qt, Qt$$section(QT.$${i}.VERSION, ., 0, 0))
++        QMAKE_PKGCONFIG_REQUIRES += $$replace(QT.$${i}.name, ^Qt, Qt$$section(QT.$${i}.VERSION, ., 0, 0))$$qtPlatformTargetSuffix()
+     isEmpty(QMAKE_PKGCONFIG_DESCRIPTION): \
+         QMAKE_PKGCONFIG_DESCRIPTION = $$replace(TARGET, ^Qt, "Qt ") module
+     pclib_replace.match = $$lib_replace.match