Fixed unit tests on computers where the first OpenCL platforms' device list is empty because it has no associated GPU devices.

All platforms with no associated devices are now deleted from the platforms vector before commencing the unit tests.
Furthermore the test now throws an exception if the list of platforms is empty.

Author: scschaefer

UnitTest/clw_test.h

@@ -47,6 +47,21 @@ class CLW : public ::testing::Test
         // Create all available platforms
         CLWPlatform::CreateAllPlatforms(platforms);
 
+        // Remove platforms that don't have any associated devices
+        for (auto it = platforms.begin(); it != platforms.end();)
+        {
+            if (it->GetDeviceCount() == 0)
+            {
+                it = platforms.erase(it);
+            }
+            else
+            {
+                ++it;
+            }
+        }
+
+        ThrowIf(platforms.empty(), CL_DEVICE_NOT_FOUND, "CLW::SetUp failed => no available OpenCL platforms with at least 1 device!");
+
         // Try to find AMD platform and set a flag if found
         bool       amdctx_ = false;
         for (int i = 0; i < platforms.size(); ++i)