RFR: 8343056: C2: Micro-optimize Node lists grow

[Aleksey Shipilev]

Seen this in Leyden profiles, but it is a generic issue. The profiles show `Node::grow` and `VectorSet::grow` as hot methods. The methods are small, and since they are implementing doubling-the-array scheme, we often exit early without actually growing. Outlining the actual growing part from the capacity check would allow inlining the common case.

I'll put some performance data in the comments.

Additional testing:
 - [x] Linux x86_64 server fastdebug, `tier1`

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/21707/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21707&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343056
  Stats: 27 lines in 4 files changed: 14 ins; 6 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/21707.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21707/head:pull/21707

PR: https://git.openjdk.org/jdk/pull/21707