RFR: 8303764: Turn off -Zc:wchar_t- for Visual C++ [v2]

[Julian Waters]

> security.cpp contains a few invalid implicit conversions between pointer types that will not fly when the permissive- compiler option is active. Given that permissive- will become the Visual C++ compiler's default mode of operation in the future, it is better to handle this now so future compiler upgrades will not cause issues. Problems here are very easily solved with explicit casts

Julian Waters has updated the pull request incrementally with two additional commits since the last revision:

 - -Zc:wchar_t should be enabled
 - Remove explicit wchar_t check in jdk.accessibility

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12907/files
  - new: https://git.openjdk.org/jdk/pull/12907/files/29068054..e33c9c4d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12907&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12907&range=00-01

  Stats: 4 lines in 2 files changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/12907.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12907/head:pull/12907

PR: https://git.openjdk.org/jdk/pull/12907