fix two new syntax-check failures

[Jim Meyering]

These changes fix two syntax-check failures.
One was due to this tight-scope issue:

  floor_log2
  floor_log2
  floor_log2
  floor_log2
  make[1]: *** [/diffutils/tight-scope.mk:42: _gl_tight_scope] Error 1

The other was due files with uses of functions in alloca.h all of
which were newer than maint.mk's old regexp.

>From 608a613abd577c52ccf22644f211e7bad78b5061 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@meta.com>
Date: Tue, 6 Jun 2023 21:49:24 -0700
Subject: [PATCH 1/2] maint: avoid new tight-scope syntax-check failure

* src/system.h (floor_log2): Declare with "SYSTEM_INLINE int"
on the same line as the function name, to accommodate the
tight-scope syntax-check rule.
* cfg.mk (_gl_TS_extern): Add SYSTEM_INLINE to the regexp.
---
 cfg.mk       | 2 +-
 src/system.h | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/cfg.mk b/cfg.mk
index 8c9bab5..3713860 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -74,4 +74,4 @@ exclude_file_name_regexp--sc_space_tab = ^gl/lib/.*\.c\.diff$$
 exclude_file_name_regexp--sc_prohibit_doubled_word = ^tests/y2038-vs-32bit$$

 # Tell gnulib's tight_scope rule that we mark externs with XTERN
-export _gl_TS_extern = extern|XTERN|DIFF_INLINE
+export _gl_TS_extern = extern|XTERN|DIFF_INLINE|SYSTEM_INLINE
diff --git a/src/system.h b/src/system.h
index ce4758d..f82ae61 100644
--- a/src/system.h
+++ b/src/system.h
@@ -212,8 +212,7 @@ verify (LIN_MAX <= IDX_MAX);
 #define STREQ(a, b) (strcmp (a, b) == 0)

 /* Return the floor of the log base 2 of N.  Return -1 if N is zero.  */
-SYSTEM_INLINE int
-floor_log2 (idx_t n)
+SYSTEM_INLINE int floor_log2 (idx_t n)
 {
   verify (IDX_MAX <= ULLONG_MAX);
   return ULLONG_WIDTH - 1 - count_leading_zeros_ll (n);
-- 
2.41.0


>From 0d2ea921b3b4ed125368ce886e121c179eae42a7 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@meta.com>
Date: Tue, 6 Jun 2023 21:49:46 -0700
Subject: [PATCH 2/2] build: update gnulib to latest (for maint.mk syntax-check
 fix)

---
 gnulib | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gnulib b/gnulib
index 0e26367..1496e1f 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 0e2636700a641556256a37fca0e7d6f472f83bb4
+Subproject commit 1496e1fbe5bd7a9302d9168e9dc1864f1e435547
-- 
2.41.0