[jdk17u-dev] RFR: 8277822: Remove debug-only heap overrun checks in os::malloc and friends

[Thomas Stuefe]

After we backported "8275320: NMT should perform buffer overrun checks", I'd like to backport this one as well.This change removes now redundant overrun checks from os::malloc and friends. 

Not a clean backport, but the fix is small. There had been a security fix: "8286519: Better memory handling" sits in the middle of the backporting chains. It did introduce a size overflow check that I had to move and adapt (lines 694-697).


  // Check for overflow.
  if (outer_size < size) {
    return NULL;
  }

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

Commit messages:
 - Backport 39b1d75f25ff2cc348f8b69d4e280847c6843ae2

Changes: https://git.openjdk.org/jdk17u-dev/pull/1041/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1041&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8277822
  Stats: 189 lines in 6 files changed: 35 ins; 101 del; 53 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1041.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/1041/head:pull/1041

PR: https://git.openjdk.org/jdk17u-dev/pull/1041