Make QProcess::splitCommand accept QStringView, as per header review

A static function that only parses the string to create the list, so
no need for a QString overload.

Change-Id: I1df297adb795095d6eec94ccfcad52498178a7b1
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

src/corelib/io/qprocess.cpp

@@ -2255,7 +2255,7 @@ void QProcessPrivate::start(QIODevice::OpenMode mode)
     Tokens with spaces can be surrounded by double quotes; three
     consecutive double quotes represent the quote character itself.
 */
-QStringList QProcess::splitCommand(const QString &command)
+QStringList QProcess::splitCommand(QStringView command)
 {
     QStringList args;
     QString tmp;

src/corelib/io/qprocess.h

@@ -282,7 +282,7 @@ public:
 
     static QString nullDevice();
 
-    static QStringList splitCommand(const QString &command);
+    static QStringList splitCommand(QStringView command);
 
 public Q_SLOTS:
     void terminate();