Use the "enum hack" to fix the SmiTagging constants.

test/compiler-unittests/change-lowering-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/compiler/typer.h"
 #include "test/compiler-unittests/graph-unittest.h"
@@ skipping 41 matching lines @@
     }
     UNREACHABLE();
     return 0;
   }
   int SmiMaxValue() const { return -(SmiMinValue() + 1); }
   int SmiMinValue() const {
     return static_cast<int>(0xffffffffu << (SmiValueSize() - 1));
   }
   int SmiShiftAmount() const { return kSmiTagSize + SmiShiftSize(); }
   int SmiShiftSize() const {
-    // TODO(turbofan): Work-around for weird GCC 4.6 linker issue:
-    // src/compiler/change-lowering.cc:46: undefined reference to
-    // `v8::internal::SmiTagging<4u>::kSmiShiftSize'
-    // src/compiler/change-lowering.cc:46: undefined reference to
-    // `v8::internal::SmiTagging<8u>::kSmiShiftSize'
-    STATIC_ASSERT(SmiTagging<4>::kSmiShiftSize == 0);
-    STATIC_ASSERT(SmiTagging<8>::kSmiShiftSize == 31);
-    return Is32() ? 0 : 31;
+    return Is32() ? SmiTagging<4>::SmiShiftSize()
+                  : SmiTagging<8>::SmiShiftSize();
   }
   int SmiValueSize() const {
-    // TODO(turbofan): Work-around for weird GCC 4.6 linker issue:
-    // src/compiler/change-lowering.cc:46: undefined reference to
-    // `v8::internal::SmiTagging<4u>::kSmiValueSize'
-    // src/compiler/change-lowering.cc:46: undefined reference to
-    // `v8::internal::SmiTagging<8u>::kSmiValueSize'
-    STATIC_ASSERT(SmiTagging<4>::kSmiValueSize == 31);
-    STATIC_ASSERT(SmiTagging<8>::kSmiValueSize == 32);
-    return Is32() ? 31 : 32;
+    return Is32() ? SmiTagging<4>::SmiValueSize()
+                  : SmiTagging<8>::SmiValueSize();
   }
 
   Node* Parameter(int32_t index = 0) {
     return graph()->NewNode(common()->Parameter(index), graph()->start());
   }
 
   Reduction Reduce(Node* node) {
     Typer typer(zone());
     JSGraph jsgraph(graph(), common(), &typer);
     CompilationInfo info(isolate(), zone());
@@ skipping 379 matching lines @@
               IsIfTrue(AllOf(CaptureEq(&branch),
                              IsBranch(IsUint32LessThanOrEqual(
                                           val, IsInt32Constant(SmiMaxValue())),
                                       graph()->start()))),
               AllOf(CaptureEq(&if_false), IsIfFalse(CaptureEq(&branch))))));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8