Treat hoisted temp variables as a custom prologue

Author: rbuckton

src/compiler/transformer.ts

@@ -327,6 +327,8 @@ namespace ts {
                         createVariableDeclarationList(lexicalEnvironmentVariableDeclarations)
                     );
 
+                    setEmitFlags(statement, EmitFlags.CustomPrologue);
+
                     if (!statements) {
                         statements = [statement];
                     }

tests/baselines/reference/asyncArrowFunction11_es5.js

@@ -53,7 +53,8 @@ var A = /** @class */ (function () {
                 args[_i] = arguments[_i];
             }
             return __awaiter(_this, void 0, void 0, function () {
-                var _a, obj;
+                var obj;
+                var _a;
                 var _this = this;
                 return __generator(this, function (_b) {
                     switch (_b.label) {

tests/baselines/reference/asyncArrowFunction8_es5.js

@@ -6,7 +6,8 @@ var foo = async (): Promise<void> => {
 //// [asyncArrowFunction8_es5.js]
 var _this = this;
 var foo = function () { return __awaiter(_this, void 0, void 0, function () {
-    var _a, v;
+    var v;
+    var _a;
     return __generator(this, function (_b) {
         switch (_b.label) {
             case 0:

tests/baselines/reference/asyncFunctionDeclaration9_es5.js

@@ -6,7 +6,8 @@ async function foo(): Promise<void> {
 //// [asyncFunctionDeclaration9_es5.js]
 function foo() {
     return __awaiter(this, void 0, void 0, function () {
-        var _a, v;
+        var v;
+        var _a;
         return __generator(this, function (_b) {
             switch (_b.label) {
                 case 0:

tests/baselines/reference/bindingPatternOmittedExpressionNesting.js

@@ -3,8 +3,8 @@ export let [,,[,[],,[],]] = undefined as any;
 
 //// [bindingPatternOmittedExpressionNesting.js]
 "use strict";
-exports.__esModule = true;
 var _a, _b, _c, _d;
+exports.__esModule = true;
 exports._e = (_a = undefined, _b = _a[2], _c = _b[1], _d = _b[3]);
 
 

tests/baselines/reference/blockScopedBindingsInDownlevelGenerator.js

@@ -45,7 +45,8 @@ var __values = (this && this.__values) || function (o) {
     };
 };
 function a() {
-    var e_1, _a, _loop_1, _b, _c, i, e_1_1;
+    var _loop_1, _a, _b, i, e_1_1;
+    var e_1, _c;
     return __generator(this, function (_d) {
         switch (_d.label) {
             case 0:
@@ -64,17 +65,17 @@ function a() {
                 _d.label = 1;
             case 1:
                 _d.trys.push([1, 6, 7, 8]);
-                _b = __values([1, 2, 3]), _c = _b.next();
+                _a = __values([1, 2, 3]), _b = _a.next();
                 _d.label = 2;
             case 2:
-                if (!!_c.done) return [3 /*break*/, 5];
-                i = _c.value;
+                if (!!_b.done) return [3 /*break*/, 5];
+                i = _b.value;
                 return [5 /*yield**/, _loop_1(i)];
             case 3:
                 _d.sent();
                 _d.label = 4;
             case 4:
-                _c = _b.next();
+                _b = _a.next();
                 return [3 /*break*/, 2];
             case 5: return [3 /*break*/, 8];
             case 6:
@@ -83,7 +84,7 @@ function a() {
                 return [3 /*break*/, 8];
             case 7:
                 try {
-                    if (_c && !_c.done && (_a = _b.return)) _a.call(_b);
+                    if (_b && !_b.done && (_c = _a.return)) _c.call(_a);
                 }
                 finally { if (e_1) throw e_1.error; }
                 return [7 /*endfinally*/];

tests/baselines/reference/compoundExponentiationAssignmentLHSIsValue.js

@@ -148,9 +148,8 @@ _a = Math.pow(['', ''], value), '' = _a[0], '' = _a[1];
 var Derived = /** @class */ (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = this;
         var _a;
-        _this = _super.call(this) || this;
+        var _this = _super.call(this) || this;
         (_a = _super.prototype). = Math.pow(_a., value);
         return _this;
     }

tests/baselines/reference/declarationEmitComputedNameCausesImportToBePainted.js

@@ -20,8 +20,8 @@ exports.__esModule = true;
 exports.Key = Symbol();
 //// [index.js]
 "use strict";
-exports.__esModule = true;
 var _a;
+exports.__esModule = true;
 var context_1 = require("./context");
 exports.context = (_a = {},
     _a[context_1.Key] = 'bar',

tests/baselines/reference/declarationEmitComputedNameConstEnumAlias.js

@@ -24,8 +24,8 @@ var EnumExample;
 exports["default"] = EnumExample;
 //// [index.js]
 "use strict";
-exports.__esModule = true;
 var _a;
+exports.__esModule = true;
 var EnumExample_1 = require("./EnumExample");
 exports["default"] = (_a = {},
     _a[EnumExample_1["default"].TEST] = {},

tests/baselines/reference/declarationEmitPrivateSymbolCausesVarDeclarationEmit2.js

@@ -25,8 +25,8 @@ exports.__esModule = true;
 exports.x = Symbol();
 //// [b.js]
 "use strict";
-exports.__esModule = true;
 var _a;
+exports.__esModule = true;
 var a_1 = require("./a");
 var C = /** @class */ (function () {
     function C() {
@@ -51,8 +51,8 @@ var __extends = (this && this.__extends) || (function () {
         d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
     };
 })();
-exports.__esModule = true;
 var _a;
+exports.__esModule = true;
 var a_1 = require("./a");
 var b_1 = require("./b");
 var D = /** @class */ (function (_super) {