[WASM] Implemented Wasm unhandled exceptions on JS site

libraries/stdlib/wasm/internal/kotlin/wasm/internal/ExceptionHelpers.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.wasm.internal
+
+@JsFun(
+"""(message, wasmTypeName, stack) => { 
+        const error = new Error();
+        error.message = message;
+        error.name = wasmTypeName;
+        error.stack = stack;
+        throw error;
+   }"""
+)
+private external fun throwJsError(message: String?, wasmTypeName: String?, stack: String)
+
+internal fun throwAsJsException(t: Throwable): Nothing {
+    throwJsError(t.message, t::class.simpleName, t.stackTraceToString())
+    return error("Unreachable")
+}
+
+internal var isNotFirstWasmExportCall: Boolean = false