Add NGROUPS.
Historical code still uses this, and people work around its absence
locally. All of iOS/macOS and musl/glibc have this.
Change-Id: I119834f535b346275be5fa1df3c323eee9e242cc
diff --git a/libc/include/sys/param.h b/libc/include/sys/param.h
index 79ae067..1c991ae 100644
--- a/libc/include/sys/param.h
+++ b/libc/include/sys/param.h
@@ -41,8 +41,11 @@
/** The unit of `st_blocks` in `struct stat`. */
#define DEV_BSIZE 512
-/** A historical name for PATH_MAX. */
-#define MAXPATHLEN PATH_MAX
+/** A historical name for PATH_MAX. Use PATH_MAX in new code. */
+#define MAXPATHLEN PATH_MAX
+
+/** A historical name for NGROUPS_MAX. Use NGROUPS_MAX in new code. */
+#define NGROUPS NGROUPS_MAX
#define MAXSYMLINKS 8