Extract DiagnosticReporter implementation from Compiler.

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 /**
  * The [LiveRange] class covers a range where an instruction is live.
  */
 class LiveRange {
@@ skipping 191 matching lines @@
   /**
    * The live intervals of instructions.
    */
   final Map<HInstruction, LiveInterval> liveIntervals;
 
   SsaLiveIntervalBuilder(
       this.compiler, this.generateAtUseSite, this.controlFlowOperators)
     : liveInstructions = new Map<HBasicBlock, LiveEnvironment>(),
       liveIntervals = new Map<HInstruction, LiveInterval>();
 
+  DiagnosticReporter get reporter => compiler.reporter;
+
   void visitGraph(HGraph graph) {
     visitPostDominatorTree(graph);
     if (!liveInstructions[graph.entry].isEmpty) {
-      compiler.internalError(CURRENT_ELEMENT_SPANNABLE, 'LiveIntervalBuilder.');
+      reporter.internalError(CURRENT_ELEMENT_SPANNABLE, 'LiveIntervalBuilder.');
     }
   }
 
   void markInputsAsLiveInEnvironment(HInstruction instruction,
                                      LiveEnvironment environment) {
     for (int i = 0, len = instruction.inputs.length; i < len; i++) {
       markAsLiveInEnvironment(instruction.inputs[i], environment);
     }
   }
 
@@ skipping 481 matching lines @@
       if (!needsName(input)) {
         names.addAssignment(predecessor, input, phi);
       } else {
         names.addCopy(predecessor, input, phi);
       }
     }
 
     namer.allocateName(phi);
   }
 }