Deserialize ResolvedAsts and ResolutionImpacts only when needed for compilation.

pkg/compiler/lib/src/universe/call_structure.dart

Index: pkg/compiler/lib/src/universe/call_structure.dart
diff --git a/pkg/compiler/lib/src/universe/call_structure.dart b/pkg/compiler/lib/src/universe/call_structure.dart
index 84c0a62d08a4d7346c057e0718fac2e50382dee2..a96622e74f8c5f50be490255828d22a234adfd48 100644
--- a/pkg/compiler/lib/src/universe/call_structure.dart
+++ b/pkg/compiler/lib/src/universe/call_structure.dart
@@ -38,6 +38,17 @@ class CallStructure {
     return new NamedCallStructure(argumentCount, namedArguments);
   }
 
+  /// Creates the [CallStructure] corresponding to calling [signature] as
+  /// declared, that is, all named arguments are in the order of declaration.
+  factory CallStructure.fromSignature(FunctionSignature signature) {
+    List<String> namedParameters;
+    if (signature.optionalParametersAreNamed) {
+      namedParameters =
+          signature.optionalParameters.map((e) => e.name).toList();
+    }
+    return new CallStructure(signature.parameterCount, namedParameters);
+  }
+
   /// `true` if this call has named arguments.
   bool get isNamed => false;
 
@@ -220,13 +231,7 @@ class CallStructure {
 
     // Synthesize a structure for the call.
     // TODO(ngeoffray): Should the resolver do it instead?
-    List<String> namedParameters;
-    if (signature.optionalParametersAreNamed) {
-      namedParameters =
-          signature.optionalParameters.map((e) => e.name).toList();
-    }
-    CallStructure callStructure =
-        new CallStructure(signature.parameterCount, namedParameters);
+    CallStructure callStructure = new CallStructure.fromSignature(signature);
     if (!callStructure.signatureApplies(signature)) {
       return false;
     }