The common pattern is to use

* @run <current-class-name>
For example,
vmTestbase/vm/compiler/optimizations/stringconcat/implicit/Merge01/cs_enabled/TestDescription.java:33: * @run main/othervm -XX:+CompactStrings vm.compiler.optimizations.stringconcat.implicit.Merge01

This enhancement is to allow using ${this} to expand to current class in jtreg tags to simplify the line to
* @run main/othervm -XX:+CompactStrings ${this}

We might want to have several `this` entities
${this.class}
and
${this.filename}
to use in the compile tag. Why it might be needed?