[Gradle, JS] Add workaround for debugging with webpack 5

^KT-45621 fixed

libraries/tools/kotlin-test-js-runner/webpack-5-debug.js

@@ -0,0 +1,26 @@
+"use strict";
+
+const {SourceMapSource} = require("webpack-sources");
+const {absolutify} = require("webpack/lib/util/identifier");
+
+// https://github.com/webpack/webpack/issues/12951
+class PatchSourceMapSourcePlugin {
+    apply(compiler) {
+        compiler.hooks.beforeRun.tap("PathcSourceMapSourcePlugin", compiler => {
+            const original = SourceMapSource.prototype._ensureSourceMapObject;
+
+            SourceMapSource.prototype._ensureSourceMapObject = function () {
+                original.call(this)
+                this._sourceMapAsObject.sources = this._sourceMapAsObject
+                    .sources
+                    .map(source => {
+                        if (!source.startsWith("webpack://")) return source
+
+                        return absolutify(compiler.options.context, source.slice(10))
+                    })
+            }
+        });
+    }
+}
+
+module.exports = PatchSourceMapSourcePlugin;