Build separate native and WASI pipelines with shared multicall names

Checkpoint before integration and package validation.

Assisted-by: SurmAgent:unknown [read] [edit] [bash]

userland/qjs/source/tests/function_source.js

@@ -0,0 +1,14 @@
+"use strict"
+const expect = "function f() { return 42 }"
+function f() { return 42 }
+
+{
+    const actual = f.toString()
+    if (actual !== expect) throw Error(actual)
+}
+
+{
+    const f = eval(expect + "f")
+    const actual = f.toString()
+    if (actual !== expect) throw Error(actual)
+}