Improve diagnostic messages for reading image header.

Differentiate between missing file, read error and invalid
image header. This should help distinguish incremental build
errors due to missing dependencies (invalid image header due
to image version change) from other infrastructure problems.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 143205070
Change-Id: I529705c8049f75793aab373976e6fa5e0f980bab
1 file changed