Add kernel_offset to all expressions; Make KernelConstMapKeyEqualsTraits use kernel_offset

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 990a4b7c411c9b5d458bc664f043408eb087a372..4ef5572e973ebd63ed0a80213a3a9027e95e872a 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -1484,7 +1484,7 @@ bool ConstantEvaluator::GetCachedConstant(TreeNode* node, Instance* value) {
     return false;
   }
   KernelConstantsMap constants(script_.compile_time_constants());
-  *value ^= constants.GetOrNull(node, &is_present);
+  *value ^= constants.GetOrNull(node->kernel_offset(), &is_present);
   // Mutator compiler thread may add constants while background compiler
   // is running, and thus change the value of 'compile_time_constants';
   // do not assert that 'compile_time_constants' has not changed.
@@ -1516,7 +1516,7 @@ void ConstantEvaluator::CacheConstantValue(TreeNode* node,
     script_.set_compile_time_constants(array);
   }
   KernelConstantsMap constants(script_.compile_time_constants());
-  constants.InsertNewOrGetValue(node, value);
+  constants.InsertNewOrGetValue(node->kernel_offset(), value);
   script_.set_compile_time_constants(constants.Release());
 }