GH-617 patch AdapterInfo.findCommonLoader() to use context class loader

Author: thurka

visualvm/nashorn.jdk15/nbproject/project.properties

@@ -7,5 +7,5 @@ nbm.module.author=Tomas Hurka
 nbm.needs.restart=true
 release.external/nashorn-core-15.4.jar=modules/ext/nashorn-core-15.4.jar
 release.external/asm-util-9.7.jar=modules/ext/asm-util-9.7.jar
-javac.source=1.8
+javac.source=1.15
 javac.compilerargs=-Xlint -Xlint:-serial