Perform more C warning fixup on all C source files and headers.

winsup/testsuite/winsup.api/ltp/wait401.c

@@ -64,13 +64,14 @@
 #include <sys/resource.h>
 #include <sys/wait.h>
 
-void cleanup(void);
+void cleanup(void) __attribute__((noreturn));
 void setup(void);
 
-char *TCID= "wait401()";
+const char *TCID= "wait401()";
 int TST_TOTAL = 1;
 extern int Tst_count;
 
+int
 main(int ac, char **av)
 {
 	int lc;				/* loop counter */