RFR: JDK-8298448: UndefinedBehaviorSanitizer [v9]

[Justin King]

> Allow building OpenJDK with UBSan. Currently the build fails when optimizing the image due to lots of undefined behavior (it invokes the built JVM). Follow up PRs will either replace the undefined behavior with well defined behavior or suppress errors which are intentional. The goal is to make OpenJDK more well defined and thus more portable across compilers and architectures.

Justin King has updated the pull request incrementally with one additional commit since the last revision:

  Update approach based on feedback from @magicus
  
  Signed-off-by: Justin King <jcking at google.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11604/files
  - new: https://git.openjdk.org/jdk/pull/11604/files/f4f8c093..f5dc2e69

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11604&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11604&range=07-08

  Stats: 148 lines in 6 files changed: 109 ins; 34 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/11604.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11604/head:pull/11604

PR: https://git.openjdk.org/jdk/pull/11604