[code-reflection] RFR: Fix lowering type pattern

[Mourad Abbay]

The lowering of TypePattern was performing unnecessary check by invoking inexistent method on ExactConversionSupport e.g. `isIntToIntExact.

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Commit messages:
 - Test we don't perform check for primitive identity conversion
 - Fix the logic of isNarrowingPrimitiveConversion

Changes: https://git.openjdk.org/babylon/pull/772/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=772&range=00
  Stats: 3 lines in 2 files changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/babylon/pull/772.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/772/head:pull/772

PR: https://git.openjdk.org/babylon/pull/772