Document that VG_(newSWA) never returns NULL (because its
allocation function does not). Audit call sites.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14533 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/pub_tool_sparsewa.h b/include/pub_tool_sparsewa.h
index a37edf7..f918eb2 100644
--- a/include/pub_tool_sparsewa.h
+++ b/include/pub_tool_sparsewa.h
@@ -50,7 +50,8 @@
 
 typedef  struct _SparseWA  SparseWA; /* opaque */
 
-// Create a new one, using the specified allocator/deallocator
+// Create a new one, using the specified allocator/deallocator.
+// Never returns NULL.
 SparseWA* VG_(newSWA) ( void*(*alloc_nofail)(const HChar* cc, SizeT), 
                         const HChar* cc,
                         void(*dealloc)(void*) );