Port "explicitly disallow using in ambient contexts"

internal/checker/grammarchecks.go

@@ -1700,8 +1700,13 @@ func (c *Checker) checkGrammarVariableDeclarationList(declarationList *ast.Varia
 	}
 
 	blockScopeFlags := declarationList.Flags & ast.NodeFlagsBlockScoped
-	if (blockScopeFlags == ast.NodeFlagsUsing || blockScopeFlags == ast.NodeFlagsAwaitUsing) && ast.IsForInStatement(declarationList.Parent) {
-		return c.grammarErrorOnNode(declarationList.AsNode(), core.IfElse(blockScopeFlags == ast.NodeFlagsUsing, diagnostics.The_left_hand_side_of_a_for_in_statement_cannot_be_a_using_declaration, diagnostics.The_left_hand_side_of_a_for_in_statement_cannot_be_an_await_using_declaration))
+	if blockScopeFlags == ast.NodeFlagsUsing || blockScopeFlags == ast.NodeFlagsAwaitUsing {
+		if ast.IsForInStatement(declarationList.Parent) {
+			return c.grammarErrorOnNode(declarationList.AsNode(), core.IfElse(blockScopeFlags == ast.NodeFlagsUsing, diagnostics.The_left_hand_side_of_a_for_in_statement_cannot_be_a_using_declaration, diagnostics.The_left_hand_side_of_a_for_in_statement_cannot_be_an_await_using_declaration))
+		}
+		if declarationList.Flags&ast.NodeFlagsAmbient != 0 {
+			return c.grammarErrorOnNode(declarationList.AsNode(), core.IfElse(blockScopeFlags == ast.NodeFlagsUsing, diagnostics.X_using_declarations_are_not_allowed_in_ambient_contexts, diagnostics.X_await_using_declarations_are_not_allowed_in_ambient_contexts))
+		}
 	}
 
 	if blockScopeFlags == ast.NodeFlagsAwaitUsing {

testdata/baselines/reference/submodule/conformance/awaitUsingDeclarations.16.errors.txt

@@ -1,24 +1,24 @@
-awaitUsingDeclarations.16.ts(2,5): error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
-awaitUsingDeclarations.16.ts(3,5): error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
-awaitUsingDeclarations.16.ts(6,5): error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
-awaitUsingDeclarations.16.ts(7,5): error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
+awaitUsingDeclarations.16.ts(2,5): error TS1546: 'await using' declarations are not allowed in ambient contexts.
+awaitUsingDeclarations.16.ts(3,5): error TS1546: 'await using' declarations are not allowed in ambient contexts.
+awaitUsingDeclarations.16.ts(6,5): error TS1546: 'await using' declarations are not allowed in ambient contexts.
+awaitUsingDeclarations.16.ts(7,5): error TS1546: 'await using' declarations are not allowed in ambient contexts.
 
 
 ==== awaitUsingDeclarations.16.ts (4 errors) ====
     declare namespace N {
         await using x: { [Symbol.asyncDispose](): Promise<void> };
-        ~~~~~
-!!! error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1546: 'await using' declarations are not allowed in ambient contexts.
         await using y: null;
-        ~~~~~
-!!! error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
+        ~~~~~~~~~~~~~~~~~~~
+!!! error TS1546: 'await using' declarations are not allowed in ambient contexts.
     }
     declare module 'M' {
         await using x: { [Symbol.asyncDispose](): Promise<void> };
-        ~~~~~
-!!! error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1546: 'await using' declarations are not allowed in ambient contexts.
         await using y: null;
-        ~~~~~
-!!! error TS2852: 'await using' statements are only allowed within async functions and at the top levels of modules.
+        ~~~~~~~~~~~~~~~~~~~
+!!! error TS1546: 'await using' declarations are not allowed in ambient contexts.
     }
 

testdata/baselines/reference/submodule/conformance/usingDeclarations.16.errors.txt

@@ -0,0 +1,24 @@
+usingDeclarations.16.ts(2,5): error TS1545: 'using' declarations are not allowed in ambient contexts.
+usingDeclarations.16.ts(3,5): error TS1545: 'using' declarations are not allowed in ambient contexts.
+usingDeclarations.16.ts(6,5): error TS1545: 'using' declarations are not allowed in ambient contexts.
+usingDeclarations.16.ts(7,5): error TS1545: 'using' declarations are not allowed in ambient contexts.
+
+
+==== usingDeclarations.16.ts (4 errors) ====
+    declare namespace N {
+        using x: { [Symbol.dispose](): void };
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1545: 'using' declarations are not allowed in ambient contexts.
+        using y: null;
+        ~~~~~~~~~~~~~
+!!! error TS1545: 'using' declarations are not allowed in ambient contexts.
+    }
+    declare module 'M' {
+        using x: { [Symbol.dispose](): void };
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1545: 'using' declarations are not allowed in ambient contexts.
+        using y: null;
+        ~~~~~~~~~~~~~
+!!! error TS1545: 'using' declarations are not allowed in ambient contexts.
+    }
+