[JS IR BE] Use fresh name for external JsModule declarations.

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameTables.kt

@@ -370,7 +370,7 @@ class NameTables(
             declaration !is IrDeclarationWithName ->
                 return
 
-            declaration.isEffectivelyExternal() ->
+            declaration.isEffectivelyExternal() && (declaration.getJsModule() == null || declaration.isJsNonModule()) ->
                 globalNames.declareStableName(declaration, declaration.getJsNameOrKotlinName().identifier)
 
             else ->

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrBoxJsTestGenerated.java

@@ -4948,6 +4948,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
             runTest("js/js.translator/testData/box/jsModule/externalFunction.kt");
         }
 
+        @TestMetadata("externalFunctionNameClash.kt")
+        public void testExternalFunctionNameClash() throws Exception {
+            runTest("js/js.translator/testData/box/jsModule/externalFunctionNameClash.kt");
+        }
+
         @TestMetadata("externalFunctionPlain.kt")
         public void testExternalFunctionPlain() throws Exception {
             runTest("js/js.translator/testData/box/jsModule/externalFunctionPlain.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java

@@ -4963,6 +4963,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             runTest("js/js.translator/testData/box/jsModule/externalFunction.kt");
         }
 
+        @TestMetadata("externalFunctionNameClash.kt")
+        public void testExternalFunctionNameClash() throws Exception {
+            runTest("js/js.translator/testData/box/jsModule/externalFunctionNameClash.kt");
+        }
+
         @TestMetadata("externalFunctionPlain.kt")
         public void testExternalFunctionPlain() throws Exception {
             runTest("js/js.translator/testData/box/jsModule/externalFunctionPlain.kt");

js/js.translator/testData/box/jsModule/externalFunctionNameClash.js

@@ -0,0 +1,5 @@
+define("lib", [], function() {
+    return function(y) {
+        return 23 + y;
+    };
+});

js/js.translator/testData/box/jsModule/externalFunctionNameClash.kt

@@ -0,0 +1,14 @@
+// EXPECTED_REACHABLE_NODES: 1284
+// MODULE_KIND: AMD
+package foo
+
+@JsModule("lib")
+external fun foo(y: Int): Int = definedExternally
+
+fun foo(y: String): String = y + "K"
+
+fun box(): String {
+    val foo10 = foo(10)
+    if (foo10 != 33) return "Fail: $foo10"
+    return "OK"
+}