RFR: 8263185: Mallinfo deprecated in glibc 2.33

[Christoph Göttschkes]

Starting with glibc 2.33, mallinfo is deprecated in favor of the new mallinfo2 API. Both APIs work the same way, the only difference is, that mallinfo2 uses size_t instead of int for the fields of the struct, containing the information about malloc. Please see the [glibc release notes](https://sourceware.org/pipermail/libc-alpha/2021-February/122207.html).

Testing with tier1 on a system with glibc 2.33 and on a system with glibc 2.31.

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Commit messages:
 - 8263185: Mallinfo deprecated in glibc 2.33

Changes: https://git.openjdk.java.net/jdk/pull/2964/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2964&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263185
  Stats: 13 lines in 1 file changed: 8 ins; 3 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2964.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2964/head:pull/2964

PR: https://git.openjdk.java.net/jdk/pull/2964