kernel/svc: Implement svcCreateEvent()

svcCreateEvent operates by creating both a readable and writable event
and then attempts to add both to the current process' handle table.

If adding either of the events to the handle table fails, then the
relevant error from the handle table is returned.

If adding the readable event after the writable event to the table
fails, then the writable event is removed from the handle table and the
relevant error from the handle table is returned.

Note that since we do not currently test resource limits, we don't check
the resource limit table yet.

src/core/hle/kernel/svc.cpp

@@ -1598,6 +1598,34 @@ static ResultCode CreateSharedMemory(Handle* handle, u64 size, u32 local_permiss
     return RESULT_SUCCESS;
 }
 
+static ResultCode CreateEvent(Handle* write_handle, Handle* read_handle) {
+    LOG_DEBUG(Kernel_SVC, "called");
+
+    auto& kernel = Core::System::GetInstance().Kernel();
+    const auto [readable_event, writable_event] =
+        WritableEvent::CreateEventPair(kernel, ResetType::Sticky, "CreateEvent");
+
+    HandleTable& handle_table = kernel.CurrentProcess()->GetHandleTable();
+
+    const auto write_create_result = handle_table.Create(writable_event);
+    if (write_create_result.Failed()) {
+        return write_create_result.Code();
+    }
+    *write_handle = *write_create_result;
+
+    const auto read_create_result = handle_table.Create(readable_event);
+    if (read_create_result.Failed()) {
+        handle_table.Close(*write_create_result);
+        return read_create_result.Code();
+    }
+    *read_handle = *read_create_result;
+
+    LOG_DEBUG(Kernel_SVC,
+              "successful. Writable event handle=0x{:08X}, Readable event handle=0x{:08X}",
+              *write_create_result, *read_create_result);
+    return RESULT_SUCCESS;
+}
+
 static ResultCode ClearEvent(Handle handle) {
     LOG_TRACE(Kernel_SVC, "called, event=0x{:08X}", handle);
 
@@ -1806,7 +1834,7 @@ static const FunctionDef SVC_Table[] = {
     {0x42, nullptr, "ReplyAndReceiveLight"},
     {0x43, nullptr, "ReplyAndReceive"},
     {0x44, nullptr, "ReplyAndReceiveWithUserBuffer"},
-    {0x45, nullptr, "CreateEvent"},
+    {0x45, SvcWrap<CreateEvent>, "CreateEvent"},
     {0x46, nullptr, "Unknown"},
     {0x47, nullptr, "Unknown"},
     {0x48, nullptr, "MapPhysicalMemoryUnsafe"},

src/core/hle/kernel/svc_wrap.h

@@ -59,6 +59,19 @@ void SvcWrap() {
     FuncReturn(retval);
 }
 
+template <ResultCode func(u32*, u32*)>
+void SvcWrap() {
+    u32 param_1 = 0;
+    u32 param_2 = 0;
+    const u32 retval = func(&param_1, &param_2).raw;
+
+    auto& arm_interface = Core::CurrentArmInterface();
+    arm_interface.SetReg(1, param_1);
+    arm_interface.SetReg(2, param_2);
+
+    FuncReturn(retval);
+}
+
 template <ResultCode func(u32*, u64)>
 void SvcWrap() {
     u32 param_1 = 0;