Fix snprintf configure test for clang 15

Clang 15 -Wimplicit-int defaults to an error in C99 mode and above.
A handful of tests have "main(..." and not "int main(..." which caused
the tests to produce incorrect results.

diff --git a/configure.ac b/configure.ac
index de60a1b1fe806a46900e9bf25c500aef9ec10c39..165c49de43236a18a6cf7737c95c9b3f9a5897a3 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -713,7 +713,7 @@ case "$host" in
        AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <mach-o/dyld.h>
 #include <stdlib.h>
-main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
+int main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
                exit(0);
        else
                exit(1);
@@ -4259,7 +4259,7 @@ dnl test snprintf (broken on SCO w/gcc)
 #include <stdlib.h>
 #include <string.h>
 #ifdef HAVE_SNPRINTF
-main()
+int main()
 {
        char buf[50];
        char expected_out[50];
@@ -4276,7 +4276,7 @@ main()
        exit(0);
 }
 #else
-main() { exit(0); }
+int main() { exit(0); }
 #endif
                ]])], [ true ], [ AC_DEFINE([BROKEN_SNPRINTF]) ],
                AC_MSG_WARN([cross compiling: Assuming working snprintf()])