Suppress Valgrind warnings for leaks about wargv

The `wargv` array is allocated in `main()` and possibly freed in
`main()`, but its elements are intentionally leaked because some of them
are used for the lifetime of the program. Suppress the warnings about
these leaks in the Valgrind suppression file.

Author: magicant

tests/valgrind.supp

@@ -28,6 +28,43 @@
    ...
    fun:getpwnam_r@@GLIBC_2.2.5
 }
+{
+   Memcheck:Leak:wargv_element
+   Memcheck:Leak
+   match-leak-kinds: definite,possible
+   fun:malloc
+   fun:xmalloc
+   fun:xmallocn
+   fun:xmalloce
+   fun:wb_initwithmax
+   fun:wb_init
+   fun:malloc_mbstowcs
+   fun:main
+}
+{
+   Memcheck:Leak:wargv_element_reallocated
+   Memcheck:Leak
+   match-leak-kinds: definite,possible
+   fun:realloc
+   fun:xrealloc
+   fun:xreallocn
+   fun:xrealloce
+   fun:wb_setmax
+   fun:wb_ensuremax
+   fun:wb_mbscat
+   fun:malloc_mbstowcs
+   fun:main
+}
+{
+   Memcheck:Leak:wargv
+   Memcheck:Leak
+   match-leak-kinds: definite
+   fun:malloc
+   fun:xmalloc
+   fun:xmallocn
+   fun:xmalloce
+   fun:main
+}
 {
    Memcheck:Leak:open_redirections
    Memcheck:Leak