RFR: 7904079: Fix setting up length parameter for CXUnsavedFiles Struct [v5]

[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 updated the pull request incrementally with one additional commit since the last revision:

  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/812861a0..6043e0dd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=04
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=03-04

  Stats: 52 lines in 3 files changed: 17 ins; 19 del; 16 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