[code-reflection] RFR: Remove the code model transformation: addVarsWhenNecessary. [v2]

[Mourad Abbay]

> We remove the code model transformation: `addVarsWhenNecessary`.

Mourad Abbay has updated the pull request incrementally with four additional commits since the last revision:

 - Refactor.
 - All InvokeOps (we can have) can be me mapped to JCExpression directly.
 - The mapping of returnValue to tree is not going to be requested, so no need to store it.
 - Map ArrayStoreOp to a JCExpression.

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Changes:
  - all: https://git.openjdk.org/babylon/pull/387/files
  - new: https://git.openjdk.org/babylon/pull/387/files/1645e037..cae6c352

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=387&range=01
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=387&range=00-01

  Stats: 8 lines in 1 file changed: 1 ins; 4 del; 3 mod
  Patch: https://git.openjdk.org/babylon/pull/387.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/387/head:pull/387

PR: https://git.openjdk.org/babylon/pull/387