Add java/util/Vector::indexOf #634

Job	Run time
rust_ci (macos-latest, stable)	50s
rust_ci (macos-latest, beta)	1m 15s
rust_ci (ubuntu-latest, stable)	57s
rust_ci (ubuntu-latest, beta)	51s
rust_ci (windows-latest, beta)	1m 52s
rust_ci (windows-latest, stable)	1m 52s
	7m 37s

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