[Wasm] Fix transforming setField in an inline class constructor body

IrSetField was transformed to its value to preserve side effects
This transformation produced invalid IR in cases where
IrSetField used in Unit-returning expression context.

This commit fixes it by producing Unit-typed expression

^KT-59084 Fixed

compiler/testData/codegen/boxWasmJsInterop/kt59084.kt

@@ -0,0 +1,18 @@
+// TARGET_BACKEND: WASM
+
+inline class JsDynamic(val value: JsAny?)
+
+val JsAny?.jsDyn: JsDynamic get() = JsDynamic(this)
+
+fun test(): Boolean {
+    val jsDynamic: JsAny? = 1.toJsNumber()
+    val jsDyn = jsDynamic.jsDyn
+    return jsDyn.value == jsDynamic
+}
+
+fun box(): String {
+    if (!test()) {
+        return "Fail"
+    }
+    return "OK"
+}