Refactor wimpy feature (#2507)

- Make it a common parameter in harness using either '-w', '--wimpy' or
'CL_WIMPY_MODE' environment variable.
- Remove all test specific wimpy variable.

---------

Co-authored-by: Kévin Petit <kpet@free.fr>

test_conformance/device_execution/host_queue_order.cpp

@@ -17,6 +17,7 @@
 #include <string.h>
 #include "harness/testHarness.h"
 #include "harness/typeWrappers.h"
+#include "harness/parseParameters.h"
 
 #include <algorithm>
 #include <vector>
@@ -24,8 +25,6 @@
 #include "utils.h"
 #include <time.h>
 
-extern int gWimpyMode;
-
 #ifdef CL_VERSION_2_0
 
 static const char* enqueue_block_first_kernel[] =