[PATCH] diagnostics: fix gcc-urlifier.cc bootstrap failure [PR112379]

[Sergei Trofimovich <slyich@gmail.com>]

From: Sergei Trofimovich <siarheit@google.com>

Without the change `./configure --enable-checking=release` bootstrap
fails as:

    gcc/gcc-urlifier.cc:100:1: error: 'get_url_suffix_for_quoted_text()'
        defined but not used [-Werror=unused-function]

This happens because the helper is used only in `ASSERT` macros which
don't always get expanded to executable code.

The fix marks helper function with `ATTRIBUTE_UNUSED`.

gcc/
	PR bootstrap/112379
	* gcc-urlifier.cc (get_url_suffix_for_quoted_text): Mark as
	ATTRIBUTE_UNUSED.
---
 gcc/gcc-urlifier.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/gcc-urlifier.cc b/gcc/gcc-urlifier.cc
index 269246bc703..0dbff985313 100644
--- a/gcc/gcc-urlifier.cc
+++ b/gcc/gcc-urlifier.cc
@@ -37,7 +37,8 @@ public:
   char *get_url_for_quoted_text (const char *p, size_t sz) const final override;
 
   const char *get_url_suffix_for_quoted_text (const char *p, size_t sz) const;
-  const char *get_url_suffix_for_quoted_text (const char *p) const;
+  /* We use ATTRIBUTE_UNUSED as this helper is called only from ASSERTs.  */
+  const char *get_url_suffix_for_quoted_text (const char *p) const ATTRIBUTE_UNUSED;
 
 private:
   static char *
-- 
2.42.0