More code review changes.

* Add more overflow checks in table/memory initialization.
* Comment for `with_allocation_strategy` to explain ignored `Config` options.
* Fix Wasmtime `Table` to not panic for type mismatches in `fill`/`copy`.
* Add tests for that fix.

tests/all/table.rs

@@ -11,3 +11,42 @@ fn get_none() {
     }
     assert!(table.get(1).is_none());
 }
+
+#[test]
+fn fill_wrong() {
+    let store = Store::default();
+    let ty = TableType::new(ValType::FuncRef, Limits::new(1, None));
+    let table = Table::new(&store, ty, Val::FuncRef(None)).unwrap();
+    assert_eq!(
+        table
+            .fill(0, Val::ExternRef(None), 1)
+            .map_err(|e| e.to_string())
+            .unwrap_err(),
+        "mismatched element fill type"
+    );
+
+    let ty = TableType::new(ValType::ExternRef, Limits::new(1, None));
+    let table = Table::new(&store, ty, Val::ExternRef(None)).unwrap();
+    assert_eq!(
+        table
+            .fill(0, Val::FuncRef(None), 1)
+            .map_err(|e| e.to_string())
+            .unwrap_err(),
+        "mismatched element fill type"
+    );
+}
+
+#[test]
+fn copy_wrong() {
+    let store = Store::default();
+    let ty = TableType::new(ValType::FuncRef, Limits::new(1, None));
+    let table1 = Table::new(&store, ty, Val::FuncRef(None)).unwrap();
+    let ty = TableType::new(ValType::ExternRef, Limits::new(1, None));
+    let table2 = Table::new(&store, ty, Val::ExternRef(None)).unwrap();
+    assert_eq!(
+        Table::copy(&table1, 0, &table2, 0, 1)
+            .map_err(|e| e.to_string())
+            .unwrap_err(),
+        "tables do not have the same element type"
+    );
+}