fix(44637): add spaces between exports assignment equal token (#44655)

src/services/formatting/rules.ts

@@ -459,6 +459,9 @@ namespace ts.formatting {
             // equal in import a = module('a');
             // falls through
             case SyntaxKind.ImportEqualsDeclaration:
+            // equal in export = 1
+            // falls through
+            case SyntaxKind.ExportAssignment:
             // equal in let a = 0
             // falls through
             case SyntaxKind.VariableDeclaration:

tests/cases/fourslash/formatExportAssignment.ts

@@ -0,0 +1,6 @@
+/// <reference path="fourslash.ts"/>
+
+////export='foo';
+
+format.document();
+verify.currentFileContentIs(`export = 'foo';`);