RFR: 8343148: C2: Refactor uses of "PhaseValue::*con*() + PhaseIdealLoop::set_ctrl()" into separate method [v4]

[theoweidmannoracle]

> This patch introduces the methods `PhaseIdealLoop::intcon` and `PhaseIdealLoop::longcon` which are wrappers for:
> 
> 
> ConINode* node = _igvn.intcon(i);
> set_ctrl(node, C->root());
> 
> 
> and
> 
> 
> ConLNode* node = _igvn.longcon(i);
> set_ctrl(node, C->root());
> 
> 
> Occurrences of this pattern in loopnode.cpp were replaced with the appropriate call to the new methods.

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

  Add set_root_as_ctrl

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/21836/files
  - new: https://git.openjdk.org/jdk/pull/21836/files/798a6172..3dc3befd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21836&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21836&range=02-03

  Stats: 23 lines in 6 files changed: 4 ins; 6 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/21836.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21836/head:pull/21836

PR: https://git.openjdk.org/jdk/pull/21836