[PowerAssert] Add codegen tests

plugins/power-assert/testData/helpers/InfixDispatch.kt

@@ -0,0 +1,12 @@
+package infix.dispatch
+
+class Wrapper<V>(
+  private val value: V,
+) {
+    infix fun mustEqual(expected: V): Unit = assert(value == expected)
+
+    fun mustEqual(expected: V, message: () -> String): Unit =
+        assert(value == expected, message)
+
+    override fun toString() = "Wrapper"
+}