add tests for clGetSVMSuggestedTypeIndexKHR (#2338)

Note, this PR is setup to merge to the `cl_khr_unified_svm` branch.

Adds tests for getting a suggested SVM type index. This is the next item
on the `cl_khr_unified_svm` test plan.

test_conformance/SVM/CMakeLists.txt

@@ -20,6 +20,7 @@ set(${MODULE_NAME}_SOURCES
     test_unified_svm_capabilities.cpp
     test_unified_svm_apis.cpp
     test_unified_svm_api_query_defaults.cpp
+    test_unified_svm_api_suggested_type_index.cpp
 )
 
 set_gnulike_module_compile_flags("-Wno-sometimes-uninitialized -Wno-sign-compare")