Use jcmd.exe from JDK under test

[Mesbah-Alam]

• Use jcmd.exe from JDK under test, not from Java in PATH
• Resolves https://github.com/eclipse-openj9/openj9-systemtest/issues/146

Signed-off-by: Mesbah Alam Mesbah_Alam@ca.ibm.com

[Mesbah-Alam]

1. Grinder on (x64 Windows) reproduces the original "hang" issue and demonstrates use of jcmd.exe from Java Under test: Grinder/30957.

DLT 17:32:11.498 - Completed 100.0%. Number of tests started=103 (+0)
DLT 17:32:28.232 - **POSSIBLE HANG DETECTED**
STF 17:32:28.690 - **FAILED** Process DLT has hung
STF 17:32:28.691 - Collecting dumps for: DLT
STF 17:32:28.699 - Running command: C:/Users/jenkins/workspace/Grinder_testList_0/openjdkbinary/j2sdk-image/bin/java -XshowSettings:properties -version
STF 17:32:28.699 - Redirecting stderr to C:\temp\k95VJUgaob\java_properties.stderr
STF 17:32:28.699 - Redirecting stdout to C:\temp\k95VJUgaob\java_properties.stdout
STF 17:32:28.729 - Monitoring processes: stf::stfUtility->getJavaProperties
STF 17:32:30.243 - Monitoring Report Summary:
STF 17:32:30.243 -   o Process stf::stfUtility->getJavaProperties ended sucessfully
STF 17:32:30.247 - Using jcmd.exe to generate .DMP files
STF 17:32:30.248 - Running command: C:\Users\jenkins\workspace\Grinder_testList_0\openjdkbinary\j2sdk-image\bin\jcmd.exe 5172 Dump.java

2. Grinder on x64 Linux: Grinder/Grinder/30965.

[Mesbah-Alam]

@Peter_Shipton@ca.ibm.com - could you please review?