##### SUMMARY
When using SSH against a Windows host with PowerShell v5 the stderr when pipelining is not being used contains a nested CLIXML message in the stderr. We should be able to handle this correctly and not fail.

Currently I can only explicitly disable pipelining for Windows as it should always be enabled but there is a report where this has happened in the wild so it's not unheard of https://github.com/ansible/awx/issues/6990.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
ssh
powershell

##### ANSIBLE VERSION
```paste below
devel
```

##### CONFIGURATION
Not sure yet, need to figure out how pipelining was disabled on the Windows case.

##### OS / ENVIRONMENT
Targeting Windows Server with PowerShell v5 and the SSH default shell is `powershell.exe`


##### STEPS TO REPRODUCE
Not sure yet, can only replicate by connecting to SSH on a WIndows host and manually changing https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/connection/ssh.py#L464 to False.

##### EXPECTED RESULTS
Works just fine


##### ACTUAL RESULTS
Fails because the stderr looks like (see nested CLIXML header)
```paste below
b'#< CLIXML\r\n#< CLIXML\r\n<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04"><Obj S="progress" RefId="0"><TN RefId="0"><T>System.Management.Automation.PSCustomObject</T><T>System.Object</T></TN><MS><I64 N="SourceId">1</I64><PR N="Record"><AV>Preparing modules for first use.</AV><AI>0</AI><Nil /><PI>-1</PI><PC>-1</PC><T>Completed</T><SR>-1</SR><SD> </SD></PR></MS></Obj></Objs><Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04"><Obj S="progress" RefId="0"><TN RefId="0"><T>System.Management.Automation.PSCustomObject</T><T>System.Object</T></TN><MS><I64 N="SourceId">1</I64><PR N="Record"><AV>Preparing modules for first use.</AV><AI>0</AI><Nil /><PI>-1</PI><PC>-1</PC><T>Completed</T><SR>-1</SR><SD> </SD></PR></MS></Obj><Obj S="progress" RefId="1"><TNRef RefId="0" /><MS><I64 N="SourceId">2</I64><PR N="Record"><AV>Preparing modules for first use.</AV><AI>0</AI><Nil /><PI>-1</PI><PC>-1</PC><T>Completed</T><SR>-1</SR><SD> </SD></PR></MS></Obj></Objs>')
```

multiple_stream = b'#< CLIXML\r\n<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04">' \
                      b'<S S="Error">fake : The term \'fake\' is not recognized as the name of a cmdlet. Check _x000D__x000A_</S>' \
                      b'<S S="Error">the spelling of the name, or if a path was included._x000D__x000A_</S>' \
                      b'<S S="Error">At line:1 char:1_x000D__x000A_</S>' \
                      b'<S S="Error">+ fake cmdlet_x000D__x000A_</S><S S="Error">+ ~~~~_x000D__x000A_</S>' \
                      b'<S S="Error">    + CategoryInfo          : ObjectNotFound: (fake:String) [], CommandNotFoundException_x000D__x000A_</S>' \
                      b'<S S="Error">    + FullyQualifiedErrorId : CommandNotFoundException_x000D__x000A_</S><S S="Error"> _x000D__x000A_</S>' \
                      b'<S S="Info">hi info</S>' \
                      b'</Objs>'
    expected = b"hi info"
    actual = _parse_clixml(multiple_stream, stream="Info")
    assert actual == expected
def test_join_path_unc():
    pwsh = ShellModule()
    unc_path_parts = ['\\\\host\\share\\dir1\\\\dir2\\', '\\dir3/dir4', 'dir5', 'dir6\\']
    expected = '\\\\host\\share\\dir1\\dir2\\dir3\\dir4\\dir5\\dir6'
    actual = pwsh.join_path(*unc_path_parts)
    assert actual == expected