Return error directly when uncompressed length is 0

If uncompressed length is 0, in function MemMap::MapAnonymous, it will generate a MemMap instance whose base_begin is nullptr.
Then, when OpenMemory, it will create a DexFile instance.
At DexFile::DexFile constructor, header_ is asigned to 0, then header_->string_ids_off_ will cause crash.

Bug: b/28856653
Test: test-art-host-gtest-dex_file_test
Signed-off-by: ganxiaolin <ganxiaolin@xiaomi.com>
Change-Id: Id37f7629f4646cbc385ef054cb83b15be4c59b00
2 files changed