[jdk11u-dev] RFR: 8221988: add possibility to build with Visual Studio 2019 [v2]

[Christoph Langer]

> This is another backport that is needed for GitHub Actions. The Runners will use a VS 2019 installation as base and use VS2017 as a minor version that is installed into the VS 2019 installation.
> Patch applies cleanly after JDK-8220445 backport, except for copyright in toolchain_windows.m4.

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.

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Changes:
  - all: https://git.openjdk.java.net/jdk11u-dev/pull/181/files
  - new: https://git.openjdk.java.net/jdk11u-dev/pull/181/files/5210d9c0..5210d9c0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=181&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=181&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/181.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/181/head:pull/181

PR: https://git.openjdk.java.net/jdk11u-dev/pull/181