RFR: JDK-8288094: cleanup old _MSC_VER handling [v2]

[Matthias Baesken]

> We still handle at a number of places ancient historic _MSC_VER versions of Visual Studio releases e.g. pre VS2013 (VS2013 has _MSC_VER 1800).
> This should be cleaned up, as long as it is not 3rd party code that we don't want to adjust.
> 
> Currently still supported ("valid") VS version are 2017+, see https://github.com/openjdk/jdk/blob/master/make/autoconf/toolchain_microsoft.m4 .
> VALID_VS_VERSIONS="2019 2017 2022"
> Even with adjusted toolchain m4 files, something older than VS2013 (also probably older than VS2015) would not be able to build jdk anymore.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  use round directly

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9105/files
  - new: https://git.openjdk.org/jdk/pull/9105/files/ee8dc996..e97c8329

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=9105&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=9105&range=00-01

  Stats: 21 lines in 3 files changed: 0 ins; 17 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/9105.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9105/head:pull/9105

PR: https://git.openjdk.org/jdk/pull/9105