Follow-up of issue #5463 (String API change in JDK 11)

[michelou]

Same error and same fix as for issue #5463:

> java -version
openjdk version "11.0.2" 2019-01-15
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.2+9)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.2+9, mixed mode, sharing)

> sbt compile
[...]
[info] Test run started
[info] Test xsbt.ExtractUsedNamesSpecification.extractSymbolicNames started
[error] W:\dotty\compiler\test\dotty\tools\vulpix\ParallelTesting.scala:779:105: value toList is not a member of java.util.stream.Stream[String]
[error]             (error.pos.span.toString + " in " + error.pos.source.file.name) :: error.getMessage().lines.toList
[error]                                                                                                         ^

[error] one error found

[dottybot]

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Have an awesome day! ☀️

[allanrenucci]

Thanks!