Kernel: Add placement new[] operator

AK/kmalloc.h

@@ -84,6 +84,11 @@ inline void* operator new(size_t, void* ptr)
 {
     return ptr;
 }
+
+inline void* operator new[](size_t, void* ptr)
+{
+    return ptr;
+}
 #    endif
 
 #endif