Add LINE_MAX.

LINE_MAX is a bad idea from the 1970s that we've ignored until now,
but there's already one hack in the AOSP tree (external/ltp) to work
around its absence, and kselftests would need another. Both uses are
bad code, but bad code exists, and iOS/macOS and musl/glibc all have
the same 2048 value, and it is in POSIX, so at least it's consistent
idiocy. Hopefully we're not encouraging more of it!

Bug: https://github.com/llvm/llvm-project/issues/88119
Change-Id: Ief219c3fe20b3d95da7040c4b9411f997b1c0470
diff --git a/tests/headers/posix/limits_h.c b/tests/headers/posix/limits_h.c
index 7e92d81..0ca80a5 100644
--- a/tests/headers/posix/limits_h.c
+++ b/tests/headers/posix/limits_h.c
@@ -130,10 +130,10 @@
   MACRO(CHARCLASS_NAME_MAX);
   MACRO(COLL_WEIGHTS_MAX);
   MACRO(EXPR_NEST_MAX);
-  MACRO(LINE_MAX);
   MACRO(NGROUPS_MAX);
   MACRO(RE_DUP_MAX);
 #endif
+  MACRO(LINE_MAX);
 
   MACRO_VALUE(_POSIX_CLOCKRES_MIN, 20000000);