8165687: Fix license and copyright headers in jd9 under hotspot/test
Summary: Legal notices and Oracle copyrights were updated (white and blank space, commas) in tests files for uniformity to meet Oracle requirements.
Reviewed-by: dholmes, iris
Contributed-by: Stanislav Smirnov <stanislav.smirnov@oracle.com>, Vassili Igouchkine <vassili.igouchkine@oracle.com>

8157957: ClassNotFoundException: jdk.test.lib.JDKToolFinder
Reviewed-by: coleenp, gtriantafill, mseledtsov, iignatyev, dholmes, dsamersoff

8160088: update hotspot tests depending on GC to use @requires vm.gc.X
Reviewed-by: iignatyev, mchernov, dholmes

8154258: [TESTBUG] Various serviceability tests fail compilation
Summary: Replace sun.misc.Unsafe with jdk.internal.misc.Unsafe
Reviewed-by: chegar, kvn

8132717: Add tests checking that instances of j.l.Classes of a large size are allocated as Humongous
Reviewed-by: jmasa, dfazunen