RFR: 6542: Improve calls to render in the flame view [v16]

[Miroslav Wengner]

> stable flameview generation

Miroslav Wengner has updated the pull request incrementally with one additional commit since the last revision:

  6542: code clean up

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Changes:
  - all: https://git.openjdk.java.net/jmc/pull/78/files
  - new: https://git.openjdk.java.net/jmc/pull/78/files/3de0f0e1..8d849ca5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmc&pr=78&range=15
 - incr: https://webrevs.openjdk.java.net/?repo=jmc&pr=78&range=14-15

  Stats: 166 lines in 2 files changed: 85 ins; 33 del; 48 mod
  Patch: https://git.openjdk.java.net/jmc/pull/78.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/78/head:pull/78

PR: https://git.openjdk.java.net/jmc/pull/78