Add missing tests for statement completion values

The project contains tests for the completion value of most (but not
all) statements. Introduce tests to complete coverage of this detail.

test/language/statements/const/cptn-value.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-let-and-const-declarations-runtime-semantics-evaluation
+es6id: 13.3.1.4
+description: Returns an empty completion
+info: |
+  LexicalDeclaration : LetOrConst BindingList ;
+
+  1. Let next be the result of evaluating BindingList.
+  2. ReturnIfAbrupt(next).
+  3. Return NormalCompletion(empty).
+---*/
+
+assert.sameValue(
+  eval('const test262id1 = 1;'), undefined, 'Single declaration'
+);
+assert.sameValue(
+  eval('const test262id2 = 2, test262id3 = 3;'),
+  undefined,
+  'Multiple declarations'
+);
+
+assert.sameValue(eval('4; const test262id5 = 5;'), 4);
+assert.sameValue(eval('6; let test262id7 = 7, test262id8 = 8;'), 6);

test/language/statements/empty/cptn-value.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-empty-statement-runtime-semantics-evaluation
+es6id: 13.4.1
+description: Returns an empty completion
+info: |
+  1. Return NormalCompletion(empty).
+---*/
+
+assert.sameValue(eval(';'), undefined);
+assert.sameValue(eval('2;;'), 2);
+assert.sameValue(eval('3;;;'), 3);

test/language/statements/labeled/cptn-break.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-labelled-statements-runtime-semantics-labelledevaluation
+es6id: 13.13.14
+description: Completion value when LabelledItem returns a "break" completion
+info: |
+  LabelledStatement : LabelIdentifier : LabelledItem
+
+  1. Let label be the StringValue of LabelIdentifier.
+  2. Append label as an element of labelSet.
+  3. Let stmtResult be LabelledEvaluation of LabelledItem with argument
+     labelSet.
+  4. If stmtResult.[[Type]] is break and SameValue(stmtResult.[[Target]],
+     label) is true, then
+     a. Let stmtResult be NormalCompletion(stmtResult.[[Value]]).
+---*/
+
+assert.sameValue(eval('test262id: { 5; break test262id; 9; }'), 5);

test/language/statements/labeled/cptn-nrml.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-labelled-statements-runtime-semantics-labelledevaluation
+es6id: 13.13.14
+description: Completion value when LabelledItem returns normally
+info: |
+  LabelledStatement : LabelIdentifier : LabelledItem
+
+  1. Let label be the StringValue of LabelIdentifier.
+  2. Append label as an element of labelSet.
+  3. Let stmtResult be LabelledEvaluation of LabelledItem with argument
+     labelSet.
+  4. If stmtResult.[[Type]] is break and SameValue(stmtResult.[[Target]],
+     label) is true, then
+     [...]
+  5. Return Completion(stmtResult).
+---*/
+
+assert.sameValue(eval('test262id: 2;'), 2);

test/language/statements/let/cptn-value.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-let-and-const-declarations-runtime-semantics-evaluation
+es6id: 13.3.1.4
+description: Returns an empty completion
+info: |
+  LexicalDeclaration : LetOrConst BindingList ;
+
+  1. Let next be the result of evaluating BindingList.
+  2. ReturnIfAbrupt(next).
+  3. Return NormalCompletion(empty).
+---*/
+
+assert.sameValue(
+  eval('let test262id1;'), undefined, 'Single declaration without initializer'
+);
+assert.sameValue(
+  eval('let test262id2 = 2;'),
+  undefined,
+  'Single declaration bearing initializer'
+);
+assert.sameValue(
+  eval('let test262id3 = 3, test262id4;'),
+  undefined,
+  'Multiple declarations, final without initializer'
+);
+assert.sameValue(
+  eval('let test262id5, test262id6 = 6;'),
+  undefined,
+  'Multiple declarations, final bearing initializer'
+);
+
+assert.sameValue(eval('7; let test262id8;'), 7);
+assert.sameValue(eval('9; let test262id10 = 10;'), 9);
+assert.sameValue(eval('11; let test262id12 = 12, test262id13;'), 11);
+assert.sameValue(eval('14; let test262id15, test262id16 = 16;'), 14);

test/language/statements/variable/cptn-value.js

+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-variable-statement-runtime-semantics-evaluation
+es6id: 13.3.2.4
+description: Returns an empty completion
+info: |
+  VariableStatement : var VariableDeclarationList ;
+
+  1. Let next be the result of evaluating VariableDeclarationList.
+  2. ReturnIfAbrupt(next).
+  3. Return NormalCompletion(empty).
+---*/
+
+assert.sameValue(
+  eval('var test262id1;'), undefined, 'Single declaration without initializer'
+);
+assert.sameValue(
+  eval('var test262id2 = 2;'),
+  undefined,
+  'Single declaration bearing initializer'
+);
+assert.sameValue(
+  eval('var test262id3 = 3, test262id4;'),
+  undefined,
+  'Multiple declarations, final without initializer'
+);
+assert.sameValue(
+  eval('var test262id5, test262id6 = 6;'),
+  undefined,
+  'Multiple declarations, final bearing initializer'
+);
+
+assert.sameValue(eval('7; var test262id8;'), 7);
+assert.sameValue(eval('9; var test262id10 = 10;'), 9);
+assert.sameValue(eval('11; var test262id12 = 12, test262id13;'), 11);
+assert.sameValue(eval('14; var test262id15, test262id16 = 16;'), 14);