[Interpreter] Adds support for const/let variables to interpreter.

test/cctest/cctest.status

Index: test/cctest/cctest.status
diff --git a/test/cctest/cctest.status b/test/cctest/cctest.status
index 1062a20c001022b7ff1a5ea9df31637dc2bf6a9f..43699e97bc102eda2e02de736d6d0bdb6d9ece20 100644
--- a/test/cctest/cctest.status
+++ b/test/cctest/cctest.status
@@ -534,7 +534,6 @@
   'test-compiler/OptimizedCodeSharing3': [SKIP],
   'test-compiler/Print': [SKIP],
   'test-decls/CrossScriptDynamicLookup': [SKIP],
-  'test-decls/Regress425510': [SKIP],
   'test-feedback-vector/VectorCallICStates': [SKIP],
   'test-heap/AddInstructionChangesNewSpacePromotion': [SKIP],
   'test-heap/ArrayShiftSweeping': [SKIP],
@@ -582,12 +581,6 @@
   'test-run-jsops/ClassLiteral': [SKIP],
   'test-run-jsops/LookupLoad': [SKIP],
   'test-run-jsops/LookupStore': [SKIP],
-  'test-run-variables/ContextInitializeVariables': [SKIP],
-  'test-run-variables/ContextLoadVariables': [SKIP],
-  'test-run-variables/ContextStoreVariables': [SKIP],
-  'test-run-variables/StackInitializeVariables': [SKIP],
-  'test-run-variables/StackLoadVariables': [SKIP],
-  'test-run-variables/StackStoreVariables': [SKIP],
   'test-sampler-api/StackFramesConsistent': [SKIP],
   'test-thread-termination/TerminateAndReenterFromThreadItself': [SKIP],
   'test-thread-termination/TerminateCancelTerminateFromThreadItself': [SKIP],