[TESTBUG] hotspot test_env.sh can set VM_CPU incorrectly

Some tests, like Test8017498.sh, depend on VM_CPU being set correctly. VM_CPU is based on running "grep" on the output of -Xinternalversion. The problem is the internal version contains other information that can be mistaken for a cpu name. For example, a JPRT build has an internal version with the format <job id>.<username>.<repo name>, so you can easily get test failures if your username or repo name contain a string that test_env.sh is grepping for. Looks like the same problem exists for VM_OS and VM_TYPE.