fix Issue 22823 - dmd.root.file: File.read fails to read any file on PPC

[ibuclaw]

The druntime fix is dlang/druntime#3762, but older releases of the compiler can't be used to bootstrap as-is. This provides a stub definition of stat_t which fixes the read routines for calling stat to get file sizes correct.

stat_t is also used by dmd.lib, and dmd.common.file. But both FileMapper and Library are only used by the dmd backend.

Note, am using __VERSION__ < 2099 here, as gdc is making the jump from 2.076 (C++) to 2.099 (D). For ldc, which switched to being self hosted a long while before, retroactively fixing self-hosted PPC will be more difficult.

Edit: switched to stat_t_imported.st_size.offsetof != 48. Also fixed the stat() and fstat() definitions to be friendly towards CRuntimes that aren't glibc.

FYI @kinke.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	22823	blocker	dmd.root.file: File.read fails to read any file on PPC

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#13719"