Revert of Better pack fields in Variable (patchset #1 id:1 of...

Revert of Better pack fields in Variable (patchset #1 id:1 of https://codereview.chromium.org/2253513002/ )

Reason for revert:
Revert: Breaks ARM build: https://uberchromegw.corp.google.com/i/client.v8.ports/builders/V8%20Arm%20-%20builder/builds/2999

Original issue's description:
> Better pack fields in Variable
>
> This reduces sizeof(Variable) from 64 to 40 on x64
>
> BUG=v8:5209
>
> Committed: https://crrev.com/d84343568047c8621a6b8f88f20a7f34586321b8
> Cr-Commit-Position: refs/heads/master@{#38659}

TBR=marja@chromium.org,jkummerow@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5209

Review-Url: https://codereview.chromium.org/2249203002
Cr-Commit-Position: refs/heads/master@{#38666}

src/ast/variables.cc

@@ -34,12 +34,12 @@ Variable::Variable(Scope* scope, const AstRawString* name, VariableMode mode,
                    MaybeAssignedFlag maybe_assigned_flag)
     : scope_(scope),
       name_(name),
-      local_if_not_shadowed_(nullptr),
-      index_(-1),
-      initializer_position_(kNoSourcePosition),
       mode_(mode),
       kind_(kind),
       location_(VariableLocation::UNALLOCATED),
+      index_(-1),
+      initializer_position_(kNoSourcePosition),
+      local_if_not_shadowed_(NULL),
       force_context_allocation_(false),
       is_used_(false),
       initialization_flag_(initialization_flag),

src/ast/variables.h

@@ -17,13 +17,7 @@ namespace internal {
 // after binding and variable allocation.
 class Variable final : public ZoneObject {
  public:
-  enum Kind : uint8_t {
-    NORMAL,
-    FUNCTION,
-    THIS,
-    ARGUMENTS,
-    kLastKind = ARGUMENTS
-  };
+  enum Kind { NORMAL, FUNCTION, THIS, ARGUMENTS };
 
   Variable(Scope* scope, const AstRawString* name, VariableMode mode, Kind kind,
            InitializationFlag initialization_flag,
@@ -111,27 +105,23 @@ class Variable final : public ZoneObject {
  private:
   Scope* scope_;
   const AstRawString* name_;
+  VariableMode mode_;
+  Kind kind_;
+  VariableLocation location_;
+  int index_;
+  int initializer_position_;
+
   // If this field is set, this variable references the stored locally bound
   // variable, but it might be shadowed by variable bindings introduced by
   // sloppy 'eval' calls between the reference scope (inclusive) and the
   // binding scope (exclusive).
   Variable* local_if_not_shadowed_;
-  int index_;
-  int initializer_position_;
-
-  STATIC_ASSERT(kLastVariableMode < (1 << 3));
-  VariableMode mode_ : 3;
-  STATIC_ASSERT(kLastKind < (1 << 2));
-  Kind kind_ : 2;
-  STATIC_ASSERT(static_cast<uint8_t>(VariableLocation::kLastVariableLocation) <
-                (1 << 3));
-  VariableLocation location_ : 3;
 
   // Usage info.
-  bool force_context_allocation_ : 1;  // set by variable resolver
-  bool is_used_ : 1;
-  InitializationFlag initialization_flag_ : 2;
-  MaybeAssignedFlag maybe_assigned_ : 2;
+  bool force_context_allocation_;  // set by variable resolver
+  bool is_used_;
+  InitializationFlag initialization_flag_;
+  MaybeAssignedFlag maybe_assigned_;
 };
 }  // namespace internal
 }  // namespace v8

src/globals.h

@@ -878,7 +878,7 @@ const double kMaxSafeInteger = 9007199254740991.0;  // 2^53-1
 
 
 // The order of this enum has to be kept in sync with the predicates below.
-enum VariableMode : uint8_t {
+enum VariableMode {
   // User declared variables:
   VAR,  // declared via 'var', and 'function' declarations
 
@@ -899,12 +899,10 @@ enum VariableMode : uint8_t {
                    // variable is global unless it has been shadowed
                    // by an eval-introduced variable
 
-  DYNAMIC_LOCAL,  // requires dynamic lookup, but we know that the
-                  // variable is local and where it is unless it
-                  // has been shadowed by an eval-introduced
-                  // variable
-
-  kLastVariableMode = DYNAMIC_LOCAL
+  DYNAMIC_LOCAL  // requires dynamic lookup, but we know that the
+                 // variable is local and where it is unless it
+                 // has been shadowed by an eval-introduced
+                 // variable
 };
 
 inline bool IsDynamicVariableMode(VariableMode mode) {
@@ -926,7 +924,7 @@ inline bool IsImmutableVariableMode(VariableMode mode) {
   return mode == CONST || mode == CONST_LEGACY;
 }
 
-enum class VariableLocation : uint8_t {
+enum class VariableLocation {
   // Before and during variable allocation, a variable whose location is
   // not yet determined.  After allocation, a variable looked up as a
   // property on the global object (and possibly absent).  name() is the
@@ -959,9 +957,7 @@ enum class VariableLocation : uint8_t {
   LOOKUP,
 
   // A named slot in a module's export table.
-  MODULE,
-
-  kLastVariableLocation = MODULE
+  MODULE
 };
 
 // ES6 Draft Rev3 10.2 specifies declarative environment records with mutable
@@ -995,9 +991,14 @@ enum class VariableLocation : uint8_t {
 // The following enum specifies a flag that indicates if the binding needs a
 // distinct initialization step (kNeedsInitialization) or if the binding is
 // immediately initialized upon creation (kCreatedInitialized).
-enum InitializationFlag : uint8_t { kNeedsInitialization, kCreatedInitialized };
+enum InitializationFlag {
+  kNeedsInitialization,
+  kCreatedInitialized
+};
+
+
+enum MaybeAssignedFlag { kNotAssigned, kMaybeAssigned };
 
-enum MaybeAssignedFlag : uint8_t { kNotAssigned, kMaybeAssigned };
 
 // Serialized in PreparseData, so numeric values should not be changed.
 enum ParseErrorType { kSyntaxError = 0, kReferenceError = 1 };