macOS: Add helper function to check whether we're running under Rosetta

As described in https://developer.apple.com/documentation/apple-silicon/about-the-rosetta-translation-environment?language=objc#Determine-Whether-Your-App-Is-Running-as-a-Translated-Binary

Pick-to: 6.2
Change-Id: I16fa4be20e4a55c87c2eb760d671d27ee4de1703
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/corelib/kernel/qcore_mac.mm

@@ -54,6 +54,7 @@
 #include <cxxabi.h>
 #include <objc/runtime.h>
 #include <mach-o/dyld.h>
+#include <sys/sysctl.h>
 
 #include <qdebug.h>
 
@@ -366,6 +367,15 @@ bool qt_mac_applicationIsInDarkMode()
 #endif
     return false;
 }
+
+bool qt_mac_runningUnderRosetta()
+{
+    int translated = 0;
+    auto size = sizeof(translated);
+    if (sysctlbyname("sysctl.proc_translated", &translated, &size, nullptr, 0) == 0)
+        return translated;
+    return false;
+}
 #endif
 
 bool qt_apple_isApplicationExtension()

src/corelib/kernel/qcore_mac_p.h

@@ -188,6 +188,7 @@ private:
 
 #ifdef Q_OS_MACOS
 Q_CORE_EXPORT bool qt_mac_applicationIsInDarkMode();
+Q_CORE_EXPORT bool qt_mac_runningUnderRosetta();
 #endif
 
 #ifndef QT_NO_DEBUG_STREAM