RFR: JDK-8298298: NMT: count deltas are printed with 32-bit signed size [v4]

[Thomas Stuefe]

> Deltas for counts in NMT differential reports are shown as signed int, restricting them to +-2g. These counts are number of malloc blocks, or number of classes, or number of threads. In all cases number of physically existing somethings.
> 
> On large 64-bit machines they can conceivably overflow. Well, at least the malloc block counters. Granted, mallocing even just >2g number of 1 byte blocks costs about 40-50GB due to overhead in libc and NMT (on glibc). But it is conceivable.
> 
> Patch changes delta printing from int to ssize_t.
> 
> Note that I don't worry about overflowing SSIZE_MIN or SSIZE_MAX here. That would be ridiculous: we just cannot have that many physically existing things. Not on 64bit, not even on 32-bit where ssize_t is int, since in both cases the address space would be the limit. So, if the counters are that large, we have a different problem (probably counter overflow), and so we assert, resp. in release, ignore it.
> 
> Note we have the same problem with diff sizes. I expect [8281213](https://bugs.openjdk.org/browse/JDK-8281213) to fix that.

Thomas Stuefe has updated the pull request incrementally with one additional commit since the last revision:

  work around Windows weirdness where we cannot print INT_MIN (-2147483648)

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11568/files
  - new: https://git.openjdk.org/jdk/pull/11568/files/5bc8d60a..2d848169

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11568&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11568&range=02-03

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11568.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11568/head:pull/11568

PR: https://git.openjdk.org/jdk/pull/11568