[foreign-jextract] RFR: 8239128: Macro defines constant pointers can crash VM via jextract API

[Henry Jen]

The fundamental issue of the crash is that clang cursor/type may no longer valid after reparse another macro, and with pointer type lazily resolve the pointee type, if the clang cursor/type no longer valid, access invalid memory cause the crash.

The other issue is the a macro pointer to a record type like struct/union can cause NPE, and that cause the macro to be ignored on generation without a warning.

The fix remove the laziness from Type API perspective, but leave that as an implementation detail, so implementation of Pointer type need to figure out how to do that safely internally.

Record type in macro are reduces to void, as currently the Declaration implementation is depending on clang as well, we cannot guarantee that works after reparse.

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Commits:
 - a5893a2c: Merge remote-tracking branch 'openjdk/foreign-jextract' into foreign-jextract
 - cff2ce19: Fix pointer type macro issues
 - 6b76fb11: Merge remote-tracking branch 'openjdk/foreign-jextract' into foreign-jextract
 - b9b83364: Break SmokeTest
 - 4f91b025: Merge remote-tracking branch 'origin/foreign-jextract' into foreign-jextract
 - e9af8e78: Test cases for problematic macros

Changes: https://git.openjdk.java.net/panama-foreign/pull/21/files
 Webrev: https://webrevs.openjdk.java.net/panama-foreign/21/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8239128
  Stats: 532 lines in 11 files changed: 368 ins; 136 del; 28 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/21.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/21/head:pull/21

PR: https://git.openjdk.java.net/panama-foreign/pull/21