[Wasm] Add K2 diagnostic tests (KT-56849)

compiler/testData/diagnostics/wasmTests/wasmInterop/wasmExport.fir.kt

@@ -0,0 +1,58 @@
+import kotlin.wasm.WasmExport
+
+@WasmExport("a")
+external fun foo0(): Unit
+
+@WasmExport("a")
+fun foo1(): Int = js("42")
+
+class C() {
+    @WasmExport("a")
+    fun foo2(): Int = 42
+}
+
+@WasmExport("a")
+fun foo3(): Int = 42
+
+@WasmExport()
+fun foo4(): Int = 42
+
+@OptIn(kotlin.js.ExperimentalJsExport::class)
+@JsExport()
+@WasmExport()
+fun foo6(): Int = 42
+
+val p1 = (@WasmExport("a") fun () {})
+
+@WasmExport("a")
+fun foo7(
+p0: Unit,
+p1: String,
+p2: Any,
+p3: Int?,
+p4: Boolean?
+): Unit {
+    p0.toString()
+    p1.toString()
+    p2.toString()
+    p3.toString()
+    p4.toString()
+}
+
+@WasmExport("a")
+fun returnNullableUnit(): Unit? { return null }
+
+@WasmExport("a")
+fun returnNullableBoolean(): Boolean? { return null }
+
+@WasmExport("a")
+fun returnNullableAny(): Any?  { return null }
+
+@WasmExport("a")
+fun <T> fooGeneric(x: T): T { return x }
+
+@WasmExport("a")
+fun fooDeafultAndVararg(
+a: Int = definedExternally,
+vararg b: Int
+): Unit { b.toString() }

compiler/testData/diagnostics/wasmTests/wasmInterop/wasmImport.fir.kt

@@ -0,0 +1,49 @@
+import kotlin.wasm.WasmImport
+
+@WasmImport("a", "b")
+external fun foo0(): Unit
+
+@WasmImport("a", "b")
+fun foo1() {
+}
+
+external class C {
+    @WasmImport("a", "b")
+    fun memberFunction()
+}
+
+fun foo2() {
+    @WasmImport("a", "b")
+    fun localFun() {
+    }
+}
+
+val p1 = (@WasmImport("a", "b") fun () {})
+
+@WasmImport("a", "b")
+external fun foo3(
+    p0: Unit,
+    p1: String,
+    p2: Any,
+    p3: Int?,
+    p4: Boolean?
+): Unit
+
+
+@WasmImport("a", "b")
+external fun returnNullableUnit(): Unit?
+
+@WasmImport("a", "b")
+external fun returnNullableBoolean(): Boolean?
+
+@WasmImport("a", "b")
+external fun returnNullableAny(): Any?
+
+@WasmImport("a", "b")
+external fun <T> fooGeneric(x: T): T
+
+@WasmImport("a", "b")
+external fun fooDeafultAndVararg(
+a: Int = definedExternally,
+vararg b: Int
+): Unit