--downlevelIteration errors should mention using later targets

Author: a-tarasyuk

src/compiler/checker.ts

@@ -25209,7 +25209,7 @@ namespace ts {
                         ? downlevelIteration
                             ? Diagnostics.Type_0_is_not_an_array_type_or_does_not_have_a_Symbol_iterator_method_that_returns_an_iterator
                             : isIterable
-                                ? Diagnostics.Type_0_is_not_an_array_type_Use_compiler_option_downlevelIteration_to_allow_iterating_of_iterators
+                                ? Diagnostics.Type_0_is_not_an_array_type_or_a_string_type_Use_compiler_option_downlevelIteration_to_allow_iterating_of_iterators
                                 : Diagnostics.Type_0_is_not_an_array_type
                         : downlevelIteration
                             ? Diagnostics.Type_0_is_not_an_array_type_or_a_string_type_or_does_not_have_a_Symbol_iterator_method_that_returns_an_iterator

tests/baselines/reference/ES5For-ofTypeCheck14.errors.txt

@@ -1,8 +1,8 @@
-tests/cases/conformance/statements/for-ofStatements/ES5For-ofTypeCheck14.ts(2,17): error TS2568: Type 'Set<number>' is not an array type. Use compiler option '--downlevelIteration' to allow iterating of iterators.
+tests/cases/conformance/statements/for-ofStatements/ES5For-ofTypeCheck14.ts(2,17): error TS2568: Type 'Set<number>' is not an array type. Either use the '--downlevelIteration' compiler option to allow iterating on iterators, or set the '--target' option to 'es2015' or above.
 
 
 ==== tests/cases/conformance/statements/for-ofStatements/ES5For-ofTypeCheck14.ts (1 errors) ====
     var union: string | Set<number>
     for (const e of union) { }
                     ~~~~~
-!!! error TS2568: Type 'Set<number>' is not an array type. Use compiler option '--downlevelIteration' to allow iterating of iterators.
+!!! error TS2568: Type 'Set<number>' is not an array type. Either use the '--downlevelIteration' compiler option to allow iterating on iterators, or set the '--target' option to 'es2015' or above.