Implement the memory.fill instruction from the bulk memory proposal

build.rs

@@ -184,7 +184,9 @@ fn ignore(testsuite: &str, testname: &str, strategy: &str) -> bool {
 
             ("bulk_memory_operations", "table_copy")
             | ("bulk_memory_operations", "table_init")
-            | ("bulk_memory_operations", "elem") => return false,
+            | ("bulk_memory_operations", "elem")
+            | ("bulk_memory_operations", "memory_copy")
+            | ("bulk_memory_operations", "memory_fill") => return false,
             ("bulk_memory_operations", _) => return true,
 
             _ => {}