Implement proper module linking.

test/mjsunit/harmony/module-resolution.js

Index: test/mjsunit/harmony/module-resolution.js
diff --git a/test/mjsunit/harmony/module-resolution.js b/test/mjsunit/harmony/module-resolution.js
index a1b991749cfd90452d3a484ca81311aa1293a9c1..1a95347d145c53195a50c3130e6fae67d7f5efbf 100644
--- a/test/mjsunit/harmony/module-resolution.js
+++ b/test/mjsunit/harmony/module-resolution.js
@@ -33,6 +33,7 @@
 
 print("begin.")
 
+
 export let x = print("0")
 
 export module B = A.B
@@ -44,15 +45,25 @@ export module A {
     module BB = B
     export BB, x
     let x = print("2")
-    let y = print("3")
+    var y = print("3")
     let Ax = A.x
+    try { A.y } catch (e) {}  // throws
+    let Az = A.z  // undefined
+    let Az2 = z  // undefined
+    A.g()  // hoisted
+    g()  // hoisted
     let ABx = A.B.x
-    let Ay = A.y
+    let ABy = A.B.y
+    let Bx = B.x
+    let By = B.y
     let BBx = BB.x
+    let BBy = BB.y
     let Af = A.f
     function f(x,y) { return x }
   }
   export let y = print("4")
+  export var z = print("4.1")
+  export function g() {}
   let Ax = A.x
   let Bx = B.x
   let ABx = A.B.x
@@ -92,6 +103,8 @@ export module E {
   let Bx = B.x
   // TODO(rossberg): Handle import *.
   // import A.*
+  module B = A.B
+  let y = A.y
 }
 
 export module M1 {