git: openjdk/mobile: 8242237: Improve JVM TI HiddenClasses tests

[duke]

Changeset: 223ca800
Author:    Serguei Spitsyn <sspitsyn at openjdk.org>
Date:      2020-04-28 02:37:15 +0000
URL:       https://git.openjdk.java.net/mobile/commit/223ca800

8242237: Improve JVM TI HiddenClasses tests

Improve JVM TI HiddenClasses test: cleanup + more comments

Reviewed-by: lmesnik, amenkov

! test/hotspot/jtreg/serviceability/jvmti/HiddenClass/P/Q/HiddenClassSigTest.java
! test/hotspot/jtreg/serviceability/jvmti/HiddenClass/libHiddenClassSigTest.cpp