RFR: 8269685: Optimize HeapHprofBinWriter implementation

[Lin Zang]

This PR rewrite the implementation of the HeapHprofBinWriter, which could simplify the logic of current implementation.
please see detail description at https://bugs.openjdk.java.net/browse/JDK-8269685.

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Commit messages:
 - 8269685: Optimize HeapHprofBinWriter implementation

Changes: https://git.openjdk.java.net/jdk/pull/4666/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4666&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8269685
  Stats: 468 lines in 3 files changed: 209 ins; 246 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4666.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4666/head:pull/4666

PR: https://git.openjdk.java.net/jdk/pull/4666