Access NativeData only through ClosedWorld

pkg/compiler/lib/src/ssa/codegen.dart

Index: pkg/compiler/lib/src/ssa/codegen.dart
diff --git a/pkg/compiler/lib/src/ssa/codegen.dart b/pkg/compiler/lib/src/ssa/codegen.dart
index 20163ce776ddf4b2ee8320a8a635b45398187239..e66c7226f6d31ade50d006e4a86fcf78ae46021a 100644
--- a/pkg/compiler/lib/src/ssa/codegen.dart
+++ b/pkg/compiler/lib/src/ssa/codegen.dart
@@ -80,7 +80,6 @@ class SsaCodeGeneratorTask extends CompilerTask {
           backend.emitter,
           backend.nativeCodegenEnqueuer,
           backend.checkedModeHelpers,
-          backend.nativeData,
           backend.interceptorData,
           backend.oneShotInterceptorData,
           backend.rtiSubstitutions,
@@ -107,7 +106,6 @@ class SsaCodeGeneratorTask extends CompilerTask {
           backend.emitter,
           backend.nativeCodegenEnqueuer,
           backend.checkedModeHelpers,
-          backend.nativeData,
           backend.interceptorData,
           backend.oneShotInterceptorData,
           backend.rtiSubstitutions,
@@ -153,7 +151,6 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
   final CodeEmitterTask _emitter;
   final native.NativeCodegenEnqueuer _nativeEnqueuer;
   final CheckedModeHelpers _checkedModeHelpers;
-  final NativeData _nativeData;
   final InterceptorData _interceptorData;
   final OneShotInterceptorData _oneShotInterceptorData;
   final RuntimeTypesSubstitutions _rtiSubstitutions;
@@ -211,7 +208,6 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
       this._emitter,
       this._nativeEnqueuer,
       this._checkedModeHelpers,
-      this._nativeData,
       this._interceptorData,
       this._oneShotInterceptorData,
       this._rtiSubstitutions,
@@ -238,6 +234,8 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
 
   ConstantSystem get _constantSystem => _closedWorld.constantSystem;
 
+  NativeData get _nativeData => _closedWorld.nativeData;
+
   bool isGenerateAtUseSite(HInstruction instruction) {
     return generateAtUseSite.contains(instruction);
   }