##### 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>')
```

progress = b'#< CLIXML\r\n<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04">' \
               b'<Obj S="progress" RefId="0"><TN RefId="0"><T>System.Management.Automation.PSCustomObject</T><T>System.Object</T></TN><MS>' \
               b'<I64 N="SourceId">1</I64><PR N="Record"><AV>Preparing modules for first use.</AV><AI>0</AI><Nil />' \
               b'<PI>-1</PI><PC>-1</PC><T>Completed</T><SR>-1</SR><SD> </SD></PR></MS></Obj></Objs>'
    expected = b''
    actual = _parse_clixml(progress)
    assert actual == expected
def test_parse_clixml_single_stream():
    single_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'</Objs>'
    expected = b"fake : The term 'fake' is not recognized as the name of a cmdlet. Check \r\n" \
               b"the spelling of the name, or if a path was included.\r\n" \
               b"At line:1 char:1\r\n" \
               b"+ fake cmdlet\r\n" \
               b"+ ~~~~\r\n" \
               b"    + CategoryInfo          : ObjectNotFound: (fake:String) [], CommandNotFoundException\r\n" \
               b"    + FullyQualifiedErrorId : CommandNotFoundException\r\n "
    actual = _parse_clixml(single_stream)
    assert actual == expected
def test_parse_clixml_multiple_streams():