rawtherapee: Fix glibc-2.34 malloc build error

[ghost]

Description of changes

This patch was contributed to https://github.com/Beep6581/RawTherapee by @Floessie. It's upstream and will have to be removed once rawtherapee-5.9 is packaged.

Fixes the following build error:

<..>-glibc-2.34-115-dev/include/wchar.h:582:24: error: 'malloc' attribute argument 1 is ambiguous
  582 |   __attribute_malloc__ __attr_dealloc_fclose;

For the upstream discussion, see Beep6581/RawTherapee#6324.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.05 Release Notes (or backporting 21.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[jcumming]

Thanks for fixing this!

I would like 2 changes:

• a comment that this patch is upstreamed and to be removed for 5.9
• I can't point to the exact policy, but use fetchpatch to https://github.com/Beep6581/RawTherapee/files/6924307/fix-6324.patch.txt instead of including the whole patch.

[ghost]

@jcumming

1. Done (didn't fixup because that'll bother the upstream people, thanks Github, but I can if you want me to).
2. It wouldn't be straightforward, since the upstream commit does not cleanly apply to 5.8, and I had to modify the patch (i.e. add the last two hunks by hand since those functions are gone from the dev branch).

[jcumming]

LGTM, thanks!