tests: specify enum underlying type

Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2714>

tests/tests_generic_callbacks.cpp

@@ -12,7 +12,7 @@
 
 using xrt::auxiliary::util::GenericCallbacks;
 
-enum class MyEvent
+enum class MyEvent : std::uint8_t
 {
 	ACQUIRED = 1u << 0u,
 	LOST = 1u << 1u,
@@ -153,7 +153,7 @@ TEST_CASE("u_generic_callbacks")
 }
 
 
-enum MyCEvent
+enum class MyCEvent : std::uint8_t
 {
 	MY_C_EVENT_ACQUIRE = 1u << 0u,
 	MY_C_EVENT_LOST = 1u << 1u,

tests/tests_relation_chain.cpp

@@ -85,7 +85,7 @@ constexpr xrt_space_relation kSpaceRelationOnlyPosition = {
  *
  */
 
-enum Functions
+enum Functions : std::uint8_t
 {
 	NV,               // (Non-Identity) (Space Relation) Neither Position/Orientation Valid, Not Tracked
 	VT,               // (Non-Identity) (Space Relation) Position/Orientation Valid, Tracked