Support conversion of clamped double values for pixel arrays in Crankshaft.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 5aa5dd0bf8abab51504486883f019531a4288bec..31bde151e592605c470a90663b8e21aaa5aaaf9c 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -356,7 +356,6 @@ const char* HValue::Mnemonic() const {
 
 
 void HValue::SetOperandAt(int index, HValue* value) {
-  ASSERT(value == NULL || !value->representation().IsNone());
   RegisterUse(index, value);
   InternalSetOperandAt(index, value);
 }
@@ -590,6 +589,8 @@ void HInstruction::Verify() {
         ASSERT(cur == other_operand);
       }
     } else {
+      // If the following assert fires, you may have forgotten an
+      // AddInstruction.
       ASSERT(other_block->Dominates(cur_block));
     }
   }