Kernel: Exclude PROT_NONE regions from coredumps

As PROT_NONE regions can't be accessed by processes, and their only real
use is for reserving ranges of virtual memory, there's no point in
including them in coredumps.

Kernel/Coredump.cpp

@@ -51,6 +51,9 @@ Coredump::Coredump(NonnullRefPtr<Process> process, NonnullRefPtr<OpenFileDescrip
  if (looks_like_userspace_heap_region(*region))
  continue;
 #endif
+
+ if (region->access() == Memory::Region::Access::None)
+ continue;
  ++m_num_program_headers;
  }
  ++m_num_program_headers; // +1 for NOTE segment
@@ -128,6 +131,9 @@ ErrorOr<void> Coredump::write_program_headers(size_t notes_size)
  continue;
 #endif
 
+ if (region->access() == Memory::Region::Access::None)
+ continue;
+
  ElfW(Phdr) phdr {};
 
  phdr.p_type = PT_LOAD;
@@ -177,6 +183,9 @@ ErrorOr<void> Coredump::write_regions()
  continue;
 #endif
 
+ if (region->access() == Memory::Region::Access::None)
+ continue;
+
  region->set_readable(true);
  region->remap();
 
@@ -254,6 +263,9 @@ ErrorOr<void> Coredump::create_notes_regions_data(auto& builder) const
  continue;
 #endif
 
+ if (region->access() == Memory::Region::Access::None)
+ continue;
+
  ELF::Core::MemoryRegionInfo info {};
  info.header.type = ELF::Core::NotesEntryHeader::Type::MemoryRegionInfo;