Fix QT_HOST_LIBEXECS for cross-builds on Windows

Like for LibraryExecutables, we must default to "bin" on Windows for
HostLibraryExecutables in our generated qconfig.cpp.

Pick-to: 6.1
Fixes: QTBUG-91496
Change-Id: Ib5a4b3b3fd6192bd953e615058b482e67ad19462
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/corelib/global/qconfig.cpp.in

@@ -86,7 +86,11 @@ static const struct {
     { "Sysroot", "" },
     { "SysrootifyPrefix", "" },
     { "HostBinaries", "bin" },
+#ifdef Q_OS_WIN
+    { "HostLibraryExecutables", "bin" },
+#else
     { "HostLibraryExecutables", "libexec" },
+#endif
     { "HostLibraries", "lib" },
     { "HostData", "." },
     { "TargetSpec", "" },