Fix emit for ES6 export default class with static initializers. Fixes #5136.

src/compiler/emitter.ts

@@ -4785,8 +4785,10 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
                 // emit name if
                 // - node has a name
-                // - this is default export and target is not ES6 (for ES6 `export default` does not need to be compiled downlevel)                
-                if ((node.name || (node.flags & NodeFlags.Default && languageVersion < ScriptTarget.ES6)) && !thisNodeIsDecorated) {
+                // - this is default export and target is not ES6 (for ES6 `export default` does not need to be compiled downlevel)
+                // - this is default export with static initializers
+                if ((node.name || (node.flags & NodeFlags.Default && (languageVersion < ScriptTarget.ES6 
+                    || staticProperties.length > 0))) && !thisNodeIsDecorated) {
                     write(" ");
                     emitDeclarationName(node);
                 }

tests/baselines/reference/exportDefaultClassWithStaticPropertyAssignmentsInES6.js

@@ -0,0 +1,9 @@
+//// [exportDefaultClassWithStaticPropertyAssignmentsInES6.ts]
+export default class {
+    static z: string = "Foo";
+}
+
+//// [exportDefaultClassWithStaticPropertyAssignmentsInES6.js]
+export default class default_1 {
+}
+default_1.z = "Foo";

tests/baselines/reference/exportDefaultClassWithStaticPropertyAssignmentsInES6.symbols

@@ -0,0 +1,5 @@
+=== tests/cases/conformance/es6/classDeclaration/exportDefaultClassWithStaticPropertyAssignmentsInES6.ts ===
+export default class {
+    static z: string = "Foo";
+>z : Symbol(default.z, Decl(exportDefaultClassWithStaticPropertyAssignmentsInES6.ts, 0, 22))
+}

tests/baselines/reference/exportDefaultClassWithStaticPropertyAssignmentsInES6.types

@@ -0,0 +1,6 @@
+=== tests/cases/conformance/es6/classDeclaration/exportDefaultClassWithStaticPropertyAssignmentsInES6.ts ===
+export default class {
+    static z: string = "Foo";
+>z : string
+>"Foo" : string
+}

tests/cases/conformance/es6/classDeclaration/exportDefaultClassWithStaticPropertyAssignmentsInES6.ts

@@ -0,0 +1,4 @@
+// @target:es6
+export default class {
+    static z: string = "Foo";
+}