Add code_item_accessors-no_art-inl and use it in dexlist, dexdump

Added new helper to prevent inclusion of ART code. Removed accesses to
dex code.

Bug: 63756964
Bug: 70852830
Test: test-art-host-gtest -j40
Test: mm test-art-host-dexdump -j40

Change-Id: Ie0220df464a5cc2b81c0ee3e0483cdf2de003092