Don't create shadow-map if kObjPtrPoisoning is true

Causes Dex2oatImageTest.TestExtension gtest to fail in 64-bit.

Bug: 160737021
Test: run gtest Dex2oatImageTest.TestExtension
Change-Id: Ic255b69c18495985bd407b332a6fbd9640bc86f5
1 file changed