RFR: 8325878: Require minimum Clang version 13

[Kim Barrett]

Please review this change that updates the minimum supported version of Clang
to be used for building OpenJDK from 3.5 to 13.

This permits enabling C++17 (JDK-8314488), though Clang 5 might suffice for
that. A minimum of Clang 13 also obtains a critical bug fix for the [[noreturn]]
attribute (see JDK-8303805).

Testing: mach5 tier1, which includes building with a recent version of Xcode/clang.

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

Commit messages:
 - update minimum clang version

Changes: https://git.openjdk.org/jdk/pull/17862/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17862&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325878
  Stats: 3 lines in 3 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/17862.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17862/head:pull/17862

PR: https://git.openjdk.org/jdk/pull/17862