core: Silence Wclass-memaccess warnings

This requires making several types trivial and properly initialize
them whenever they are called.

src/core/hle/service/acc/acc.cpp

@@ -534,7 +534,7 @@ private:
         rb.Push(RESULT_SUCCESS);
     }
 
-    Common::UUID user_id;
+    Common::UUID user_id{Common::INVALID_UUID};
 };
 
 // 6.0.0+

src/core/hle/service/acc/profile_manager.cpp

@@ -227,17 +227,17 @@ void ProfileManager::CloseUser(UUID uuid) {
 
 /// Gets all valid user ids on the system
 UserIDArray ProfileManager::GetAllUsers() const {
-    UserIDArray output;
-    std::transform(profiles.begin(), profiles.end(), output.begin(),
-                   [](const ProfileInfo& p) { return p.user_uuid; });
+    UserIDArray output{};
+    std::ranges::transform(profiles, output.begin(),
+                           [](const ProfileInfo& p) { return p.user_uuid; });
     return output;
 }
 
 /// Get all the open users on the system and zero out the rest of the data. This is specifically
 /// needed for GetOpenUsers and we need to ensure the rest of the output buffer is zero'd out
 UserIDArray ProfileManager::GetOpenUsers() const {
-    UserIDArray output;
-    std::transform(profiles.begin(), profiles.end(), output.begin(), [](const ProfileInfo& p) {
+    UserIDArray output{};
+    std::ranges::transform(profiles, output.begin(), [](const ProfileInfo& p) {
         if (p.is_open)
             return p.user_uuid;
         return UUID{Common::INVALID_UUID};

src/core/hle/service/acc/profile_manager.h

@@ -23,12 +23,12 @@ using UserIDArray = std::array<Common::UUID, MAX_USERS>;
 /// Contains extra data related to a user.
 /// TODO: RE this structure
 struct ProfileData {
-    INSERT_PADDING_WORDS(1);
-    u32 icon_id{};
-    u8 bg_color_id{};
-    INSERT_PADDING_BYTES(0x7);
-    INSERT_PADDING_BYTES(0x10);
-    INSERT_PADDING_BYTES(0x60);
+    INSERT_PADDING_WORDS_NOINIT(1);
+    u32 icon_id;
+    u8 bg_color_id;
+    INSERT_PADDING_BYTES_NOINIT(0x7);
+    INSERT_PADDING_BYTES_NOINIT(0x10);
+    INSERT_PADDING_BYTES_NOINIT(0x60);
 };
 static_assert(sizeof(ProfileData) == 0x80, "ProfileData structure has incorrect size");
 
@@ -43,9 +43,9 @@ struct ProfileInfo {
 };
 
 struct ProfileBase {
-    Common::UUID user_uuid{Common::INVALID_UUID};
-    u64_le timestamp{};
-    ProfileUsername username{};
+    Common::UUID user_uuid;
+    u64_le timestamp;
+    ProfileUsername username;
 
     // Zero out all the fields to make the profile slot considered "Empty"
     void Invalidate() {