[jdk11u-dev] RFR: 8249095: tools/javac/launcher/SourceLauncherTest.java fails on Windows [v2]

[Christoph Langer]

> This is a clean backport of JDK-8249095, required to enable green runs of a GitHub Actions workflow.

Christoph Langer has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge branch 'master' into 8249095
 - 8249095: tools/javac/launcher/SourceLauncherTest.java fails on Windows
   
   Reviewed-by: jjg
 - 8209380: ARM: cleanup maybe-uninitialized and reorder compiler warnings
   
   Reviewed-by: dholmes, drwhite, tschatzl
 - 8257913: Add more known library locations to simplify Linux cross-compilation
   
   Reviewed-by: erikj
 - 8254270: linux 32 bit build doesn't compile libjdwp/log_messages.c
   
   Reviewed-by: redestad, cjplummer, dholmes, stuefe
 - 8221988: add possibility to build with Visual Studio 2019
   
   Reviewed-by: erikj, ysuenaga
 - 8220445: Support for side by side MSVC Toolset versions
   
   Co-authored-by: Ali Ince <ali.ince at gmail.com>
   Reviewed-by: tbell

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

Changes:
  - all: https://git.openjdk.java.net/jdk11u-dev/pull/187/files
  - new: https://git.openjdk.java.net/jdk11u-dev/pull/187/files/6aa29f89..6c8a2c88

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=187&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=187&range=00-01

  Stats: 1262 lines in 27 files changed: 1032 ins; 197 del; 33 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/187.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/187/head:pull/187

PR: https://git.openjdk.java.net/jdk11u-dev/pull/187