Willem871

Fix Apple Silicon build

2

Only include x86 specific headers and code when APPLESEED_X86 is defined. This fixes the build of system.cpp on Apple Silicon.

Avoid rebuilding 100+ OpenImageIO files when rerunning CMake due to rewriting the fmt proxy headers (external fmt case)

15

## Description OpenImageIO uses some proxy fmt headers, created at CMake time, that have a different content depending on using an external or the embedded fmt library. In case of...