Un-consolidate overloads for Map and WeakMap

src/lib/es2015.collection.d.ts

@@ -9,7 +9,8 @@ interface Map<K, V> {
 }
 
 interface MapConstructor {
-    new <K = any, V = any>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
+    new(): Map<any, any>;
+    new<K, V>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
     readonly prototype: Map<any, any>;
 }
 declare var Map: MapConstructor;

src/lib/es2015.iterable.d.ts

@@ -135,7 +135,7 @@ interface MapConstructor {
 interface WeakMap<K extends object, V> { }
 
 interface WeakMapConstructor {
-    new <K extends object = object, V = any>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
+    new <K extends object, V>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
 }
 
 interface Set<T> {

tests/baselines/reference/newMap.errors.txt

@@ -0,0 +1,8 @@
+tests/cases/compiler/newMap.ts(1,9): error TS2558: Expected 0-2 type arguments, but got 1.
+
+
+==== tests/cases/compiler/newMap.ts (1 errors) ====
+    new Map<string>();
+            ~~~~~~
+!!! error TS2558: Expected 0-2 type arguments, but got 1.
+

tests/baselines/reference/newMap.js

@@ -0,0 +1,6 @@
+//// [newMap.ts]
+new Map<string>();
+
+
+//// [newMap.js]
+new Map();

tests/baselines/reference/newMap.symbols

@@ -0,0 +1,4 @@
+=== tests/cases/compiler/newMap.ts ===
+new Map<string>();
+>Map : Symbol(Map, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+

tests/baselines/reference/newMap.types

@@ -0,0 +1,5 @@
+=== tests/cases/compiler/newMap.ts ===
+new Map<string>();
+>new Map<string>() : any
+>Map : MapConstructor
+

tests/cases/compiler/newMap.ts

@@ -0,0 +1,2 @@
+// @lib: es6
+new Map<string>();