Merge "Revert "Revert "Use dlopen to load oat files."""

diff --cc runtime/mem_map.cc
index 2e335dc,fa041a9..7e640c6
--- 1/runtime/mem_map.cc
--- 2/runtime/mem_map.cc
+++ b/runtime/mem_map.cc
@@@ -436,9 -436,17 +436,17 @@@ MemMap* MemMap::MapAnonymous(const char
      return nullptr;
    }
    return new MemMap(name, reinterpret_cast<uint8_t*>(actual), byte_count, actual,
 -                    page_aligned_byte_count, prot, false);
 +                    page_aligned_byte_count, prot, reuse);
  }
  
+ MemMap* MemMap::MapDummy(const char* name, uint8_t* addr, size_t byte_count) {
+   if (byte_count == 0) {
+     return new MemMap(name, nullptr, 0, nullptr, 0, 0, false);
+   }
+   const size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize);
+   return new MemMap(name, addr, byte_count, addr, page_aligned_byte_count, 0, true /* reuse */);
+ }
+ 
  MemMap* MemMap::MapFileAtAddress(uint8_t* expected_ptr, size_t byte_count, int prot, int flags,
                                   int fd, off_t start, bool reuse, const char* filename,
                                   std::string* error_msg) {