[foreign-memaccess+abi] RFR: Use switch instead of if-statements in MemoryInspection classes

[Per Minborg]

This PR proposes to use switch instead of if-statements

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Commit messages:
 - Undo change from other PR
 - Fix memory inspection classes after api change

Changes: https://git.openjdk.org/panama-foreign/pull/835/files
 Webrev: https://webrevs.openjdk.org/?repo=panama-foreign&pr=835&range=00
  Stats: 117 lines in 1 file changed: 2 ins; 42 del; 73 mod
  Patch: https://git.openjdk.org/panama-foreign/pull/835.diff
  Fetch: git fetch https://git.openjdk.org/panama-foreign.git pull/835/head:pull/835

PR: https://git.openjdk.org/panama-foreign/pull/835