RFR: 8346916: [REDO] align_up has potential overflow [v7]

[Casper Norrbin]

> Hi everyone,
> 
> The `align_up` function can potentially overflow, resulting in undefined behavior. Most use cases rely on the assumption that aligned_result >= original. To address this, I've added an assertion to verify this condition.
> 
> The original PR (#20808) missed cases where overflow checks already existed, so I've now went through usages of `align_up` and found the places with explicit checks. Most notably, #23168 added `align_up_or_null` to metaspace, but this function is also useful elsewhere. Given this, I relocated it to `align.hpp`, alongside the rest of the alignment functions.

Casper Norrbin has updated the pull request incrementally with one additional commit since the last revision:

  align comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23711/files
  - new: https://git.openjdk.org/jdk/pull/23711/files/1c9c9d1a..f52de010

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23711&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23711&range=05-06

  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23711.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23711/head:pull/23711

PR: https://git.openjdk.org/jdk/pull/23711