GDB testsuite: Fix warnings with -std=gnu11

Since upstream GCC has changed the default C language dialect to
'gnu11', it yields multiple warnings in the GDB testsuite for missing
function return types and implicit function declarations.  This patch
attempts to fix these.

gdb/testsuite/ChangeLog:

	* gdb.ada/cond_lang/foo.c (callme): Add return type.
	* gdb.base/call-sc.c (zed): Likewise.
	* gdb.base/checkpoint.c (main): Likewise.
	* gdb.base/dump.c (main): Likewise.
	* gdb.base/gcore.c (main): Likewise.
	* gdb.base/huge.c (main): Likewise.
	* gdb.base/multi-forks.c (main): Likewise.
	* gdb.base/pr10179-a.c (main): Likewise.
	* gdb.base/savedregs.c (main): Likewise.
	* gdb.base/sigaltstack.c (main): Likewise.
	* gdb.base/siginfo.c (main): Likewise.
	* gdb.base/structs.c (zed): Likewise.
	* gdb.mi/mi-stack.c (callee3, callee2, callee1, main): Likewise.
	* gdb.mi/mi-syn-frame.c (main): Likewise.
	* gdb.mi/until.c (foo, main): Likewise.
	* gdb.base/global-var-nested-by-dso.c (b_main, c_main): Declare.
	* gdb.base/solib-weak.c (foo): Declare.
	* gdb.base/attach-twice.c: Include stdio.h.
	* gdb.base/weaklib1.c: Likewise.
	* gdb.base/weaklib2.c: Likewise.
	* gdb.base/catch-signal-fork.c: Include stdio.h and sys/wait.h.
	* gdb.mi/mi-condbreak-call-thr-state-mt.c: Include stdio.h and
	unistd.h.
	* gdb.base/attach-pie-misread.c: Include stdlib.h.
	* gdb.mi/mi-exit-code.c: Likewise.
	* gdb.base/break-interp-lib.c: Include string.h.
	* gdb.base/coremaker.c: Likewise.
	* gdb.base/testenv.c: Likewise.
	* gdb.python/py-finish-breakpoint.c: Likewise.
	* gdb.base/inferior-died.c: Include sys/wait.h.
	* gdb.base/fileio.c: Include time.h.
	* gdb.base/async-shell.c: Include unistd.h.
	* gdb.base/dprintf-non-stop.c: Likewise.
	* gdb.base/info-os.c: Likewise.
	* gdb.mi/mi-console.c: Likewise.
	* gdb.mi/watch-nonstop.c: Likewise.
	* gdb.python/py-events.c: Likewise.
	* gdb.base/async.c (baz): Move up before its invocation.
	* gdb.base/code_elim2.c (my_global_func): Likewise.
	* gdb.base/skip-solib-lib.c (multiply): Likewise.
	* gdb.base/advance.c (func2): Likewise.

1 files changed, 4 insertions, 3 deletions

diff --git a/gdb/testsuite/gdb.base/checkpoint.c b/gdb/testsuite/gdb.base/checkpoint.c
index b6f7ecd9fa6..8f9d6da526a 100644
--- a/gdb/testsuite/gdb.base/checkpoint.c
+++ b/gdb/testsuite/gdb.base/checkpoint.c
@@ -17,10 +17,11 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
 
 long lines = 0;
 
-main()
+int main()
 {
   char linebuf[128];
   FILE *in, *out;
@@ -34,7 +35,7 @@ main()
   if (!in || !out)
     {
       fprintf (stderr, "File open failed\n");
-      exit (1);
+      return 1;
     }
 
   for (i = 0; ; i++)
@@ -55,5 +56,5 @@ main()
   fclose (out);
   printf ("Deleting copy.\n");	/* breakpoint 3 */
   unlink (COPY1_TXT);
-  exit (0);			/* breakpoint 4 */
+  return 0;			/* breakpoint 4 */
 }