Don't complain unless declaration emit is enabled

Author: jakebailey

src/compiler/checker.ts

@@ -41991,7 +41991,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
 
         if (
-            !(symbol.flags & (SymbolFlags.TypeLiteral | SymbolFlags.Signature))
+            getEmitDeclarations(compilerOptions)
+            && !(symbol.flags & (SymbolFlags.TypeLiteral | SymbolFlags.Signature))
             && !shouldPrintWithInitializer(node)
             && !isPrivateDeclaration(node)
             && isVisibleExternally(node)

tests/baselines/reference/importCallExpression5ES2020.errors.txt

@@ -1,4 +1,3 @@
-2.ts(2,7): error TS2856: The type of this declaration is ambiguous and may be observed as either 'string | undefined' or '"./0" | undefined'.
 2.ts(3,23): error TS7036: Dynamic import's specifier must be of type 'string', but here has type '"./0" | undefined'.
 2.ts(4,24): error TS7036: Dynamic import's specifier must be of type 'string', but here has type 'undefined'.
 2.ts(5,24): error TS7036: Dynamic import's specifier must be of type 'string', but here has type '"./1" | null'.
@@ -15,11 +14,9 @@
 ==== 1.ts (0 errors) ====
     export function backup() { return "backup"; }
 
-==== 2.ts (5 errors) ====
+==== 2.ts (4 errors) ====
     declare function bar(): boolean;
     const specify = bar() ? "./0" : undefined;
-          ~~~~~~~
-!!! error TS2856: The type of this declaration is ambiguous and may be observed as either 'string | undefined' or '"./0" | undefined'.
     let myModule = import(specify);
                           ~~~~~~~
 !!! error TS7036: Dynamic import's specifier must be of type 'string', but here has type '"./0" | undefined'.