SVM tests where the size is zero (#2431)

Here are some tests to check how SVM APIs behave when the size is zero,
see:

* https://github.com/KhronosGroup/OpenCL-Docs/issues/1403

These tests don't fail right now if some of the calls are unsuccessful.
This ensures that all sub-tests run on a given implementation.

test_conformance/SVM/CMakeLists.txt

@@ -5,6 +5,7 @@ set(${MODULE_NAME}_SOURCES
     test_allocate_shared_buffer.cpp
     test_allocate_shared_buffer_negative.cpp
     test_byte_granularity.cpp
+    test_corner_cases.cpp
     test_cross_buffer_pointers.cpp
     test_enqueue_api.cpp
     test_fine_grain_memory_consistency.cpp