RFR: 7904079: Fix setting up length parameter for CXUnsavedFiles Struct [v3]

[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 two additional commits since the last revision:

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

-------------

Changes:
  - all: https://git.openjdk.org/jextract/pull/289/files
  - new: https://git.openjdk.org/jextract/pull/289/files/798f0949..f5fbbc36

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=02
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=289&range=01-02

  Stats: 18 lines in 2 files changed: 16 ins; 0 del; 2 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