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

test/cctest/cctest.status

 # Copyright 2011 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 549 matching lines @@
   'test-profile-generator/ProfileNodeScriptId': [SKIP],
   'test-profile-generator/RecordStackTraceAtStartProfiling': [SKIP],
   'test-run-inlining/InlineTwice': [SKIP],
   'test-run-jscalls/LookupCall': [SKIP],
   'test-run-jsexceptions/ThrowMessageDirectly': [SKIP],
   'test-run-jsexceptions/ThrowMessagePosition': [SKIP],
   'test-run-jsobjects/ArgumentsRest': [SKIP],
   '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],
   'test-thread-termination/TerminateFromOtherThreadWhileMicrotaskRunning': [SKIP],
   'test-thread-termination/TerminateOnlyV8ThreadFromOtherThread': [SKIP],
   'test-thread-termination/TerminateOnlyV8ThreadFromThreadItself': [SKIP],
   'test-thread-termination/TerminateOnlyV8ThreadFromThreadItselfNoLoop': [SKIP],
   'test-thread-termination/TerminationInInnerTryCall': [SKIP],
   'test-unscopables-hidden-prototype/Unscopables': [SKIP],
 }],  # ignition == True
 
 ['ignition == True and arch == arm64', {
   'test-decls/CrossScriptReferencesHarmony': [SKIP],
   'test-js-arm64-variables/lookup_slots': [SKIP],
   'test-spaces/SizeOfFirstPageIsLargeEnough': [SKIP],
   'test-heap/AddInstructionChangesNewSpacePromotion': [SKIP],
   'test-heap/Regress538257': [SKIP],
 }],  # ignition == True and arch == arm64
 
 ]