Remove defaults table and attach defaults directly to tyvars

src/test/run-pass/default_type_parameter_default_dependent_associated_type.rs

@@ -0,0 +1,23 @@
+use std::marker::PhantomData;
+
+trait Id {
+    type This;
+}
+
+impl<A> Id for A {
+    type This = A;
+}
+
+struct Foo<X: Default = usize, Y = <X as Id>::This> {
+    data: PhantomData<(X, Y)>
+}
+
+impl<X: Default, Y> Foo<X, Y> {
+    fn new() -> Foo<X, Y> {
+        Foo { data: PhantomData }
+    }
+}
+
+fn main() {
+    let foo = Foo::new();
+}

src/test/run-pass/default_type_parameter_dependent_defaults.rs

@@ -0,0 +1,7 @@
+use std::marker::PhantomData;
+
+struct Foo<T,U=T> { data: PhantomData<(T, U)> }
+
+fn main() {
+    let foo = Foo { data: PhantomData };
+}

src/test/run-pass/default_type_parameter_struct_and_type_alias.rs

@@ -0,0 +1,30 @@
+use std::marker::PhantomData;
+
+trait TypeEq<A> {}
+impl<A> TypeEq<A> for A {}
+
+struct DeterministicHasher;
+struct RandomHasher;
+
+
+struct MyHashMap<K, V, H=DeterministicHasher> {
+    data: PhantomData<(K, V, H)>
+}
+
+impl<K, V, H> MyHashMap<K, V, H> {
+    fn new() -> MyHashMap<K, V, H> {
+        MyHashMap { data: PhantomData }
+    }
+}
+
+mod mystd {
+    use super::{MyHashMap, RandomHasher};
+    pub type HashMap<K, V, H=RandomHasher> = MyHashMap<K, V, H>;
+}
+
+fn try_me<H>(hash_map: mystd::HashMap<i32, i32, H>) {}
+
+fn main() {
+    let hash_map = mystd::HashMap::new();
+    try_me(hash_map);
+}