[Wasm] Test infra: support _commonFiles and additional .mjs

Use custom `evalToBoolean` as `eval` and `unsafeCast` are not
 available in Wasm stdlib

js/js.tests/test/org/jetbrains/kotlin/js/testOld/BasicWasmBoxTest.kt

@@ -47,6 +47,7 @@ abstract class BasicWasmBoxTest(
     private val testGroupOutputDirForCompilation = File(pathToRootOutputDir + "out/" + testGroupOutputDirPrefix)
 
     private val COMMON_FILES_NAME = "_common"
+    private val COMMON_FILES_DIR = "_commonFiles"
 
     private val extraLanguageFeatures = mapOf(
         LanguageFeature.JsAllowImplementingFunctionInterface to LanguageFeature.State.ENABLED,
@@ -98,11 +99,18 @@ abstract class BasicWasmBoxTest(
             if (File(additionalJsFile).exists()) {
                 jsFilesBefore += additionalJsFile
             }
+            val additionalMjsFile = filePath.removeSuffix(".kt") + ".mjs"
+            if (File(additionalMjsFile).exists()) {
+                mjsFiles += additionalMjsFile
+            }
 
             val localCommonFile = file.parent + "/" + COMMON_FILES_NAME + "." + KotlinFileType.EXTENSION
             val localCommonFiles = if (File(localCommonFile).exists()) listOf(localCommonFile) else emptyList()
 
-            val allSourceFiles = kotlinFiles + localCommonFiles
+            val globalCommonFilesDir = File(File(pathToTestDir).parent, COMMON_FILES_DIR)
+            val globalCommonFiles = globalCommonFilesDir.listFiles().orEmpty().map { it.absolutePath }
+
+            val allSourceFiles = kotlinFiles + localCommonFiles + globalCommonFiles
 
             val psiFiles = createPsiFiles(allSourceFiles.map { File(it).canonicalPath }.sorted())
             val config = createConfig(languageVersionSettings)

js/js.translator/testData/_commonFiles/testUtils.kt

@@ -1,6 +1,9 @@
 package testUtils
 
+@JsName("eval")
+private external fun evalToBoolean(code: String): Boolean
+
 fun isLegacyBackend(): Boolean =
     // Using eval to prevent DCE from thinking that following code depends on Kotlin module.
-    eval("(typeof Kotlin != \"undefined\" && typeof Kotlin.kotlin != \"undefined\")").unsafeCast<Boolean>()
+    evalToBoolean("(typeof Kotlin != \"undefined\" && typeof Kotlin.kotlin != \"undefined\")")
 

js/js.translator/testData/box/native/passMemberOrExtFromNative.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: WASM
 // EXPECTED_REACHABLE_NODES: 1285
 package foo