RFR: 8294245: Make Compile::print_inlining_stream stack allocated

[Johan Sjölen]

Hi,

Could I have  a review for this? It simplifies some auxiliary code in the Compile class related to its usage of stringStream. The only notable disadvantage is that Compile will take up `sizeof(stringStream) - sizeof(stringStream*)` more space on the stack.

Currently testing tier1-3 for this change, no errors yet and almost finished.

Thanks,
Johan

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Commit messages:
 - Make Compile::_print_inlining_stream stack allocated

Changes: https://git.openjdk.org/jdk/pull/10396/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10396&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294245
  Stats: 23 lines in 2 files changed: 0 ins; 13 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/10396.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10396/head:pull/10396

PR: https://git.openjdk.org/jdk/pull/10396