Fix await code action crashes when await is not in a function (#22623)

Fixes #22614

src/services/codefixes/fixAwaitInSyncFunction.ts

@@ -36,6 +36,10 @@ namespace ts.codefix {
     function getNodes(sourceFile: SourceFile, start: number): { insertBefore: Node, returnType: TypeNode | undefined } | undefined {
         const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
         const containingFunction = getContainingFunction(token);
+        if (!containingFunction) {
+            return;
+        }
+
         let insertBefore: Node | undefined;
         switch (containingFunction.kind) {
             case SyntaxKind.MethodDeclaration:

tests/cases/fourslash/codeFixAwaitShouldNotCrashIfNotInFunction.ts

@@ -0,0 +1,5 @@
+/// <reference path='fourslash.ts' />
+
+////await a
+
+verify.not.codeFixAvailable();