Annotate unused parameters in tests

Compiling the tests with -Wextra results to lots of warnings for unused
parameters. Annotate these cases with the `unused' attribute to avoid
the warnings.
diff --git a/tests/Gtest-bt.c b/tests/Gtest-bt.c
index b5f4439..57ace85 100644
--- a/tests/Gtest-bt.c
+++ b/tests/Gtest-bt.c
@@ -123,7 +123,7 @@
 }
 
 void
-foo (long val)
+foo (long val __attribute__((unused)))
 {
   do_backtrace ();
 }
@@ -160,7 +160,7 @@
 }
 
 void
-sighandler (int signal, void *siginfo, void *context)
+sighandler (int signal, void *siginfo __attribute__((unused)), void *context)
 {
   ucontext_t *uc = context;
   int sp;
@@ -200,7 +200,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   struct sigaction act;
   stack_t stk;
diff --git a/tests/Gtest-concurrent.c b/tests/Gtest-concurrent.c
index 126aced..b98b6c0 100644
--- a/tests/Gtest-concurrent.c
+++ b/tests/Gtest-concurrent.c
@@ -46,7 +46,7 @@
 char *sigusr1_sp;
 
 void
-handler (int sig)
+handler (int sig __attribute__((unused)))
 {
   unw_word_t ip;
   unw_context_t uc;
@@ -68,7 +68,7 @@
 }
 
 void *
-worker (void *arg)
+worker (void *arg __attribute__((unused)))
 {
   signal (SIGUSR1, handler);
 
@@ -102,7 +102,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   if (argc > 1)
     verbose = 1;
diff --git a/tests/Gtest-dyn1.c b/tests/Gtest-dyn1.c
index e084813..b530dd7 100644
--- a/tests/Gtest-dyn1.c
+++ b/tests/Gtest-dyn1.c
@@ -157,13 +157,13 @@
 }
 
 int
-dev_null (const char *format, ...)
+dev_null (const char *format __attribute__((unused)), ...)
 {
   return 0;
 }
 
 int
-main (int argc, char *argv[])
+main (int argc, char *argv[] __attribute__((unused)))
 {
   unw_dyn_region_info_t *region;
   unw_dyn_info_t di;
diff --git a/tests/Gtest-init.cxx b/tests/Gtest-init.cxx
index d83ddbf..18f1463 100644
--- a/tests/Gtest-init.cxx
+++ b/tests/Gtest-init.cxx
@@ -99,7 +99,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   verbose = argc > 1;
   return atexit (a);
diff --git a/tests/Gtest-resume-sig.c b/tests/Gtest-resume-sig.c
index 68e17eb..4ed42e3 100644
--- a/tests/Gtest-resume-sig.c
+++ b/tests/Gtest-resume-sig.c
@@ -127,7 +127,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   float d = 1.0;
   int n = 0;
diff --git a/tests/Gtest-trace.c b/tests/Gtest-trace.c
index 7488ee6..5145e65 100644
--- a/tests/Gtest-trace.c
+++ b/tests/Gtest-trace.c
@@ -137,7 +137,7 @@
 }
 
 void
-foo (long val)
+foo (long val __attribute__((unused)))
 {
   do_backtrace ();
 }
@@ -174,7 +174,7 @@
 }
 
 void
-sighandler (int signal, void *siginfo, void *context)
+sighandler (int signal, void *siginfo __attribute__((unused)), void *context)
 {
   ucontext_t *uc = context;
   int sp;
@@ -216,7 +216,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   struct sigaction act;
   stack_t stk;
diff --git a/tests/rs-race.c b/tests/rs-race.c
index c67584c..cf34b97 100644
--- a/tests/rs-race.c
+++ b/tests/rs-race.c
@@ -1331,7 +1331,7 @@
 }
 
 void *
-bar(void *p)
+bar(void *p __attribute__((unused)))
 {
   int i;
   for (i = 0; i < ITERS; ++i) {
@@ -1485,7 +1485,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   if (argc > 1)
     verbose = 1;
diff --git a/tests/test-async-sig.c b/tests/test-async-sig.c
index 5e90690..296d58d 100644
--- a/tests/test-async-sig.c
+++ b/tests/test-async-sig.c
@@ -158,7 +158,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   struct sigaction act;
   long i = 0;
diff --git a/tests/test-coredump-unwind.c b/tests/test-coredump-unwind.c
index 6e62b8d..841c5e1 100644
--- a/tests/test-coredump-unwind.c
+++ b/tests/test-coredump-unwind.c
@@ -261,7 +261,7 @@
 }
 
 int
-main(int argc, char **argv)
+main(int argc __attribute__((unused)), char **argv)
 {
   unw_addr_space_t as;
   struct UCD_info *ui;
diff --git a/tests/test-init-remote.c b/tests/test-init-remote.c
index ac036d1..47d9548 100644
--- a/tests/test-init-remote.c
+++ b/tests/test-init-remote.c
@@ -91,7 +91,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   verbose = (argc > 1);
 
diff --git a/tests/test-mem.c b/tests/test-mem.c
index 4f7e58c..2a24359 100644
--- a/tests/test-mem.c
+++ b/tests/test-mem.c
@@ -82,7 +82,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   struct rlimit rlim;
 
diff --git a/tests/test-proc-info.c b/tests/test-proc-info.c
index e8915fb..3c8fdea 100644
--- a/tests/test-proc-info.c
+++ b/tests/test-proc-info.c
@@ -43,15 +43,20 @@
 	{ ++errors; fprintf (stderr, args); return -1; }
 
 static int
-find_proc_info (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pip,
-		int need_unwind_info, void *arg)
+find_proc_info (unw_addr_space_t as __attribute__((unused)),
+                unw_word_t ip __attribute__((unused)),
+                unw_proc_info_t *pip __attribute__((unused)),
+                int need_unwind_info __attribute__((unused)),
+                void *arg __attribute__((unused)))
 {
   return -UNW_ESTOPUNWIND;
 }
 
 static int
-access_mem (unw_addr_space_t as, unw_word_t addr, unw_word_t *valp,
-	    int write, void *arg)
+access_mem (unw_addr_space_t as __attribute__((unused)),
+            unw_word_t addr __attribute__((unused)),
+            unw_word_t *valp, int write,
+            void *arg __attribute__((unused)))
 {
   if (!write)
     *valp = 0;
@@ -59,8 +64,10 @@
 }
 
 static int
-access_reg (unw_addr_space_t as, unw_regnum_t regnum, unw_word_t *valp,
-	    int write, void *arg)
+access_reg (unw_addr_space_t as __attribute__((unused)),
+            unw_regnum_t regnum __attribute__((unused)),
+            unw_word_t *valp, int write,
+            void *arg __attribute__((unused)))
 {
   if (!write)
     *valp = 32;
@@ -68,8 +75,10 @@
 }
 
 static int
-access_fpreg (unw_addr_space_t as, unw_regnum_t regnum, unw_fpreg_t *valp,
-	      int write, void *arg)
+access_fpreg (unw_addr_space_t as __attribute__((unused)),
+              unw_regnum_t regnum __attribute__((unused)),
+              unw_fpreg_t *valp, int write,
+              void *arg __attribute__((unused)))
 {
   if (!write)
     memset (valp, 0, sizeof (*valp));
@@ -77,27 +86,37 @@
 }
 
 static int
-get_dyn_info_list_addr (unw_addr_space_t as, unw_word_t *dilap, void *arg)
+get_dyn_info_list_addr (unw_addr_space_t as __attribute__((unused)),
+                        unw_word_t *dilap __attribute__((unused)),
+                        void *arg __attribute__((unused)))
 {
   return -UNW_ENOINFO;
 }
 
 static void
-put_unwind_info (unw_addr_space_t as, unw_proc_info_t *pi, void *arg)
+put_unwind_info (unw_addr_space_t as __attribute__((unused)),
+                 unw_proc_info_t *pi __attribute__((unused)),
+                 void *arg __attribute__((unused)))
 {
   ++errors;
   fprintf (stderr, "%s() got called!\n", __FUNCTION__);
 }
 
 static int
-resume (unw_addr_space_t as, unw_cursor_t *reg, void *arg)
+resume (unw_addr_space_t as __attribute__((unused)),
+        unw_cursor_t *reg __attribute__((unused)),
+        void *arg __attribute__((unused)))
 {
   panic ("%s() got called!\n", __FUNCTION__);
 }
 
 static int
-get_proc_name (unw_addr_space_t as, unw_word_t ip, char *buf, size_t buf_len,
-	       unw_word_t *offp, void *arg)
+get_proc_name (unw_addr_space_t as __attribute__((unused)),
+               unw_word_t ip __attribute__((unused)),
+               char *buf __attribute__((unused)),
+               size_t buf_len __attribute__((unused)),
+               unw_word_t *offp __attribute__((unused)),
+               void *arg __attribute__((unused)))
 {
   panic ("%s() got called!\n", __FUNCTION__);
 }
diff --git a/tests/test-ptrace-misc.c b/tests/test-ptrace-misc.c
index 562636a..fbbec9c 100644
--- a/tests/test-ptrace-misc.c
+++ b/tests/test-ptrace-misc.c
@@ -104,7 +104,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   int val = argc;
 
diff --git a/tests/test-setjmp.c b/tests/test-setjmp.c
index 65c343b..3054574 100644
--- a/tests/test-setjmp.c
+++ b/tests/test-setjmp.c
@@ -139,7 +139,7 @@
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   volatile sigset_t sigset1, sigset2, sigset3;
   volatile struct sigaction act;
diff --git a/tests/test-static-link-loc.c b/tests/test-static-link-loc.c
index d4a8a68..ed94f55 100644
--- a/tests/test-static-link-loc.c
+++ b/tests/test-static-link-loc.c
@@ -87,7 +87,7 @@
 #endif /* !UNW_REMOTE_ONLY */
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   if (argc > 1)
     verbose = 1;
diff --git a/tests/test-strerror.c b/tests/test-strerror.c
index 582d322..4470952 100644
--- a/tests/test-strerror.c
+++ b/tests/test-strerror.c
@@ -2,7 +2,7 @@
 #include <stdio.h>
 
 int
-main (int argc, char **argv)
+main (int argc, char **argv __attribute__((unused)))
 {
   int i, verbose = argc > 1;
   const char *msg;