RFR: 8289162: runtime/NMT/ThreadedMallocTestType.java should print out memory allocations to help debug

[Gerard Ziemski]

To help debug [JDK-8286345](https://bugs.openjdk.org/browse/JDK-8286345) it would have been extremely useful to know the values of allocated memory pointers in `runtime/NMT/ThreadedMallocTestType.java`, so let's add those.

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Commit messages:
 - fix tabs
 - add print statements to help debug

Changes: https://git.openjdk.org/jdk/pull/9675/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9675&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289162
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9675.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9675/head:pull/9675

PR: https://git.openjdk.org/jdk/pull/9675