Inline information about FS case sensitivity

As far as Qt is concerned, this information is static and depends only
on the platform. By moving the definition to the header we allow the
information to be directly used by the compiler, forgoing the need to
export the function to interested users.

Change-Id: I43de585391d41204d3c3560ac6e65e5a88aee11c
Reviewed-by: Jonas Gastal <jgastal@profusion.mobi>
Reviewed-by: Shane Kearns <ext-shane.2.kearns@nokia.com>

src/corelib/io/qfilesystemengine_p.h

@@ -63,7 +63,14 @@ QT_BEGIN_NAMESPACE
 class QFileSystemEngine
 {
 public:
-    static bool isCaseSensitive();
+    static bool isCaseSensitive()
+    {
+#ifndef Q_OS_WIN
+        return true;
+#else
+        return false;
+#endif
+    }
 
     static QFileSystemEntry getLinkTarget(const QFileSystemEntry &link, QFileSystemMetaData &data);
     static QFileSystemEntry canonicalName(const QFileSystemEntry &entry, QFileSystemMetaData &data);

src/corelib/io/qfilesystemengine_unix.cpp

@@ -87,11 +87,6 @@ static inline bool _q_isMacHidden(const char *nativePath)
 }
 #endif
 
-bool QFileSystemEngine::isCaseSensitive()
-{
-    return true;
-}
-
 //static
 QFileSystemEntry QFileSystemEngine::getLinkTarget(const QFileSystemEntry &link, QFileSystemMetaData &data)
 {

src/corelib/io/qfilesystemengine_win.cpp

@@ -472,11 +472,6 @@ void QFileSystemEngine::clearWinStatData(QFileSystemMetaData &data)
     data.lastWriteTime_ = FILETIME();
 }
 
-bool QFileSystemEngine::isCaseSensitive()
-{
-    return false;
-}
-
 //static
 QFileSystemEntry QFileSystemEngine::getLinkTarget(const QFileSystemEntry &link,
                                                   QFileSystemMetaData &data)