RFR: 7904079: Fix setting up length parameter for CXUnsavedFiles Struct [v2]

[Varada M]

> CXUnsavedFile struct contains three members, first two are pointers and last one is unsigned long. When jextract makes downcall to clang_reparseTranslationUnit_Impl it sets up the third parameter in the struct incorrectly. It sets INT instead of LONG so on big endian platform the parameter will be set differently. 
> 
> JBS Issue : [CODETOOLS-7904079](https://bugs.openjdk.org/browse/CODETOOLS-7904079)

Varada M has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  CODETOOLS-7904079: Fix setting up length parameter for CXUnsavedFiles Struct

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Changes:
  - all: https://git.openjdk.org/jextract/pull/289/files
  - new: https://git.openjdk.org/jextract/pull/289/files/8e9388d0..798f0949

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=01
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jextract/pull/289.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/289/head:pull/289

PR: https://git.openjdk.org/jextract/pull/289