INSTALL.txt: Say "macOS" instead of "Mac OS X" in modern times. Reference Issue #5407.
diff --git a/INSTALL.txt b/INSTALL.txt
index efb01d2..f570cb3 100644
--- a/INSTALL.txt
+++ b/INSTALL.txt
@@ -8,10 +8,10 @@ To compile and install SDL:
* Read the FAQ at https://wiki.libsdl.org/FAQWindows
* Run './configure; make; make install'
- Mac OS X with Xcode:
+ macOS with Xcode:
* Read docs/README-macosx.md
- Mac OS X from the command line:
+ macOS from the command line:
* Run './configure; make; make install'
Linux and other UNIX systems: