configure.in: declare as NORETURN

* configure.in (RUBY_CHECK_BUILTIN_SETJMP): declare t as NORETURN
  to suppress warnings by -Wsuggest-attribute=noreturn.
  [ruby-core:75510] [Bug #12383]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55023 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Tue May 17 11:58:58 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (RUBY_CHECK_BUILTIN_SETJMP): declare t as NORETURN
+	  to suppress warnings by -Wsuggest-attribute=noreturn.
+	  [ruby-core:75510] [Bug #12383]
+
 Tue May 17 10:40:18 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (RUBY_CHECK_SETJMP): needs the header and proper

configure.in

@@ -2603,6 +2603,9 @@ AC_CACHE_CHECK(for __builtin_setjmp, ac_cv_func___builtin_setjmp,
 	[AC_TRY_LINK([@%:@include <setjmp.h>
 	    @%:@include <stdio.h>
 	    jmp_buf jb;
+	    @%:@ifdef NORETURN
+	    NORETURN(void t(void));
+	    @%:@endif
 	    void t(void) {__builtin_longjmp($cast jb, 1);}
 	    int jump(void) {(void)(__builtin_setjmp($cast jb) ? 1 : 0); return 0;}],
 	    [