kernel+libluna: Avoid scrubbing when the memory is going to be overwritten anyway

This is the case for objects with constructors and temporary memory which is filled afterwards.

kernel/src/sys/poll.cpp

@@ -12,7 +12,7 @@ Result<u64> sys_poll(Registers*, SyscallArgs args)
     nfds_t nfds = (nfds_t)args[1];
     int timeout = (int)args[2];
 
-    struct pollfd* kfds = (struct pollfd*)TRY(malloc_impl(nfds * sizeof(pollfd)));
+    struct pollfd* kfds = (struct pollfd*)TRY(malloc_impl(nfds * sizeof(pollfd), false, false));
     auto guard = make_scope_guard([kfds] { free_impl(kfds); });
 
     if (!MemoryManager::copy_from_user(fds, kfds, nfds * sizeof(pollfd))) return err(EFAULT);

libluna/include/luna/Alloc.h

@@ -24,7 +24,7 @@
  */
 template <typename T, class... Args> [[nodiscard]] Result<T*> make(Args... args)
 {
-    T* const result = (T*)TRY(malloc_impl(sizeof(T)));
+    T* const result = (T*)TRY(malloc_impl(sizeof(T), false, false));
     new (result) T(args...);
     return result;
 }

libluna/src/Heap.cpp

@@ -425,12 +425,12 @@ void dump_heap_usage()
 #ifdef USE_FREESTANDING
 void* operator new(usize size, const std::nothrow_t&) noexcept
 {
-    return malloc_impl(size).value_or(nullptr);
+    return malloc_impl(size, false, false).value_or(nullptr);
 }
 
 void* operator new[](usize size, const std::nothrow_t&) noexcept
 {
-    return malloc_impl(size).value_or(nullptr);
+    return malloc_impl(size, false, false).value_or(nullptr);
 }
 
 void operator delete(void* p) noexcept