Revert "Library functions can never be constructors."

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index 4be5aa44bd2ab4f082cc220d51d6a916108731d9..1f608adc46032b4185a81ddfbd241eec856e27be 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -455,7 +455,10 @@ class ResolverTask extends CompilerTask {
             originParameter.parseNode(compiler).toString();
         String patchParameterText =
             patchParameter.parseNode(compiler).toString();
-        if (originParameterText != patchParameterText) {
+        if (originParameterText != patchParameterText
+            // We special case the list constructor because of the
+            // optional parameter.
+            && origin != compiler.unnamedListConstructor) {
           compiler.reportError(
               originParameter.parseNode(compiler),
               MessageKind.PATCH_PARAMETER_MISMATCH,