Completions for asserts and declare (#36355)

* Add completions for `asserts`

* Add declare assertions.

src/services/completions.ts

@@ -2525,6 +2525,7 @@ namespace ts.Completions {
             case SyntaxKind.GetKeyword:
             case SyntaxKind.SetKeyword:
             case SyntaxKind.AsyncKeyword:
+            case SyntaxKind.DeclareKeyword:
                 return true;
             default:
                 return isClassMemberModifier(kind);

src/services/utilities.ts

@@ -1283,6 +1283,7 @@ namespace ts {
 
     export const typeKeywords: readonly SyntaxKind[] = [
         SyntaxKind.AnyKeyword,
+        SyntaxKind.AssertsKeyword,
         SyntaxKind.BigIntKeyword,
         SyntaxKind.BooleanKeyword,
         SyntaxKind.FalseKeyword,