[JDK-8345428] Adapt JDK-8339113: AccessFlags can be u2 in metadata #20457

Job	Run time
/substratevm on Windows	5m 10s
/compiler style,fullbuild,test JDK21	7m 41s
/compiler build,bootstraplite JDKlatest	1h 0m 14s
/espresso style,fullbuild JDK21	13m 32s
/substratevm style,fullbuild JDK21	11m 45s
/substratevm build,helloworld,native_unittests JDKlatest	4m 7s
/substratevm build,debuginfotest JDKlatest	4m 27s
/substratevm hellomodule JDKlatest	4m 25s
/sulong style,fullbuild,sulongBasic JDK21	21m 17s
/truffle JDK21	40m 59s
/vm build,sulong JDKlatest	5m 53s
/vm build JDKlatest	5m 47s
	3h 5m 17s

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