Smali-based tests for experimental interface default methods.

This tests that interface method resolution order is correct.

Obviously needs to run under ART or a Java 8 Language runtime and compiler.

When run smali test files are generated by the util-src/generate_smali.py
script.  If we run with --jvm we will use the
$(ANDROID_BUILD_TOP)/art/tools/extract-embedded-java script to turn the smali
into equivalent Java using the embedded Java code.

Care should be taken when updating the generate_smali.py script. It should always
return equivalent output when run multiple times and the expected output should
be valid.

Do not modify the expected.txt file. It is generated on each run by
util-src/generate_smali.py.