hg: code-tools/jtharness: (regression tests) added SysEnvTest and a bit adopted SysEnv for better testability

[dmitry.bessonov at oracle.com]

Changeset: fb52e0d920c3
Author:    dbessono
Date:      2020-03-18 22:51 +0000
URL:       https://hg.openjdk.java.net/code-tools/jtharness/rev/fb52e0d920c3

(regression tests) added SysEnvTest and a bit adopted SysEnv for better testability

! src/com/sun/javatest/util/SysEnv.java
+ unit-tests/com/sun/javatest/util/SysEnvTest.java