Set-PSDebug -Trace 1 prints only first line of a multiline command

Steps to reproduce

Set-PSDebug -Trace 1

Write-Output "foo `
bar"

Expected behavior

Something like:

DEBUG:    3+  >>>> Write-Output "foo `
DEBUG:    4+  >>>> bar"

foo
bar

Actual behavior

DEBUG:    3+  >>>> Write-Output "foo `

foo
bar

Environment data

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      6.2.0-preview.1
PSEdition                      Core
GitCommitId                    6.2.0-preview.1
OS                             Microsoft Windows 10.0.17134
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Start by reproducing the issue with Set-PSDebug -Trace 1 and the multiline Write-Output command shown in the report, then locate the implementation that formats trace output. Done means the debug trace includes both lines of the multiline command while preserving the reported output.