JTReg Failures: well known file exceptions on macos/hotspot

**Describe the bug**
On mac machines for 11 and 14 hotspot the following tests are failing due to pretty much the same error
```
com/sun/jdi/ProcessAttachTest.java => JDK11 & 14
jdk/jfr/jcmd/TestJcmdStartStopDefault.java => JDK11 & 14
com/sun/jdi/ProcessAttachTest.sh => JDK8 only
```

**To Reproduce**
Steps to reproduce the behavior (or Grinder rerun link):
1. Go to https://ci.adoptopenjdk.net/view/Test_grinder/job/Grinder
2. Kick off a grinder with these parameters
- JDK8: https://ci.adoptopenjdk.net/job/Grinder/parambuild/?JDK_VERSION=8&JDK_IMPL=hotspot&BUILD_LIST=openjdk&PLATFORM=x86-64_mac&TARGET=jdk_custom&CUSTOM_TARGET=jdk/test/com/sun/jdi/ProcessAttachTest.sh
- JDK11: https://ci.adoptopenjdk.net/job/Grinder/parambuild/?JDK_VERSION=11&JDK_IMPL=hotspot&BUILD_LIST=openjdk&PLATFORM=x86-64_mac&TARGET=jdk_svc_sanity_0
- JDK14: https://ci.adoptopenjdk.net/job/Grinder/parambuild/?JDK_VERSION=14&JDK_IMPL=hotspot&BUILD_LIST=openjdk&PLATFORM=x86-64_mac&TARGET=jdk_svc_sanity_0
3. See error in console log

**Expected behavior**
Tests pass

**Screenshots**
ProcessAttachTest.java
```
01:55:19 java.io.IOException: well-known file /var/folders/rt/8_by_h8n5g9d5jhp66cf_7d80000gr/T/.java_pid18038 is not secure: file's group should be the current group (which is -1) but the group is 0
01:55:19 at jdk.jdi/com.sun.tools.jdi.ProcessAttachingConnector.attach(ProcessAttachingConnector.java:106)
01:55:19 at ProcessAttachTest.tryDebug(ProcessAttachTest.java:107)
01:55:19 at ProcessAttachTest.runTest(ProcessAttachTest.java:87)
01:55:19 at ProcessAttachTest.main(ProcessAttachTest.java:66)
01:55:19 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
01:55:19 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
01:55:19 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
01:55:19 at java.base/java.lang.reflect.Method.invoke(Method.java:566)
01:55:19 at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:298)
01:55:19 at java.base/java.lang.Thread.run(Thread.java:834)
```

TestJcmdStartStopDefault.java
```
Standard Output:

Running DCMD 'JFR.start' through 'PidJcmdExecutor'
Executing command '[/Users/jenkins/workspace/Test_openjdk11_hs_sanity.openjdk_x86-64_mac/openjdkbinary/j2sdk-image/Contents/Home/bin/../bin/jcmd, 18106, JFR.start]'
Command returned with exit code 1
---------------- stdout ----------------
18106:

---------------- stderr ----------------
java.io.IOException: well-known file /var/folders/rt/8_by_h8n5g9d5jhp66cf_7d80000gr/T/.java_pid18106 is not secure: file's group should be the current group (which is -1) but the group is 0
at jdk.attach/sun.tools.attach.VirtualMachineImpl.checkPermissions(Native Method)
at jdk.attach/sun.tools.attach.VirtualMachineImpl.(VirtualMachineImpl.java:108)
at jdk.attach/sun.tools.attach.AttachProviderImpl.attachVirtualMachine(AttachProviderImpl.java:58)
at jdk.attach/com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:207)
at jdk.jcmd/sun.tools.jcmd.JCmd.executeCommandForPid(JCmd.java:114)
at jdk.jcmd/sun.tools.jcmd.JCmd.main(JCmd.java:98)

----------------------------------------

Standard Error:

stdout: [18106:
];
stderr: [java.io.IOException: well-known file /var/folders/rt/8_by_h8n5g9d5jhp66cf_7d80000gr/T/.java_pid18106 is not secure: file's group should be the current group (which is -1) but the group is 0
at jdk.attach/sun.tools.attach.VirtualMachineImpl.checkPermissions(Native Method)
at jdk.attach/sun.tools.attach.VirtualMachineImpl.(VirtualMachineImpl.java:108)
at jdk.attach/sun.tools.attach.AttachProviderImpl.attachVirtualMachine(AttachProviderImpl.java:58)
at jdk.attach/com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:207)
at jdk.jcmd/sun.tools.jcmd.JCmd.executeCommandForPid(JCmd.java:114)
at jdk.jcmd/sun.tools.jcmd.JCmd.main(JCmd.java:98)
]
exitValue = 1

java.lang.RuntimeException: Expected to get exit value of [0]

at jdk.test.lib.process.OutputAnalyzer.shouldHaveExitValue(OutputAnalyzer.java:396)
at jdk.jfr.jcmd.JcmdHelper.jcmd(JcmdHelper.java:111)
at jdk.jfr.jcmd.JcmdHelper.jcmd(JcmdHelper.java:116)
at jdk.jfr.jcmd.TestJcmdStartStopDefault.main(TestJcmdStartStopDefault.java:50)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:834)
```

com/sun/jdi/ProcessAttachTest.sh
```
19:29:52 Exception in thread "main" java.io.IOException: well-known file /var/folders/rc/_hq7pkh54kb0dk8vvlt34pz00000gr/T/.java_pid88080 is not secure: file's group should be the current group (which is -1) but the group is 0
19:29:52 at com.sun.tools.jdi.ProcessAttachingConnector.attach(ProcessAttachingConnector.java:104)
19:29:52 at ProcessAttachDebugger.main(ProcessAttachDebugger.java:68)
19:29:52 Waiting for port file to be written...
19:29:52 Waiting 1 second(s) ...
19:29:52 Waiting 2 second(s) ...
19:29:52 Waiting 3 second(s) ...
19:29:52 Waiting 4 second(s) ...
19:29:52 Waiting 5 second(s) ...
...
Timeout!
```

**Additional context**
It appears to be a perm issue on the surface. The test is creating items in the `/var/`directory which is a sensitive directory to be creating files in. Its possible that this is likely caused by the the debugger that the test creates [not having the same perms as the java_pid file](https://stackoverflow.com/questions/9100149/jstack-well-known-file-is-not-secure).

Start by rerunning the linked Grinder jobs for com/sun/jdi/ProcessAttachTest.java, com/sun/jdi/ProcessAttachTest.sh, and jdk/jfr/jcmd/TestJcmdStartStopDefault.java on macOS JDK 8, 11, and 14, then inspect the reported well-known-file permission failure. Done means the affected JTReg tests pass on the specified macOS configurations.

Written by the indexing model from the issue text.