RFR: 8369393: NMT: poison the canaries of malloc header under ASAN build [v8]

[Afshin Zafari]

> NMT can detect malloc'd memory corruption using canary tests at header and footer of every memory region. This can only be done at free time of the memory where NNT checks the canaries and report error if they are not as expected.
> In this PR, the canary parts also are poisoned using ASAN API to get notified whenever a read/write op is done. on the canary parts. `_size` member of the malloc header is also poisoned, since it is used for finding the footer address.

Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:

  reviews applied

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27685/files
  - new: https://git.openjdk.org/jdk/pull/27685/files/cee97082..98ec45e9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27685&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27685&range=06-07

  Stats: 46 lines in 3 files changed: 8 ins; 1 del; 37 mod
  Patch: https://git.openjdk.org/jdk/pull/27685.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27685/head:pull/27685

PR: https://git.openjdk.org/jdk/pull/27685