Fix build with MinGW

I honestly can't tell why this is now needed, it seems to be related to
an update in the MinGW headers since I couldn't build previous versions
of the creator anymore too.

This pattern is already often used.

Change-Id: I81adfa2dc8fb4606b0b47a4ade5d1f5db054df9a
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/libs/utils/processinfo.cpp

@@ -13,6 +13,9 @@
 #include <unistd.h>
 #elif defined(Q_OS_WIN)
 #include "winutils.h"
+#ifdef QTCREATOR_PCH_H
+#define CALLBACK WINAPI
+#endif
 #include <windows.h>
 #include <tlhelp32.h>
 #include <psapi.h>

src/plugins/debugger/shared/hostutils.cpp

@@ -6,6 +6,9 @@
 #ifdef Q_OS_WIN
 
 #include <QTextStream>
+#ifdef QTCREATOR_PCH_H
+#define CALLBACK WINAPI
+#endif
 #include <windows.h>
 #include <utils/winutils.h>
 #include <tlhelp32.h>

src/tools/qtcdebugger/main.cpp

@@ -23,6 +23,9 @@
 
 #include <registryaccess.h>
 
+#ifdef QTCREATOR_PCH_H
+#define CALLBACK WINAPI
+#endif
 #include <windows.h>
 #include <psapi.h>