K2: Add new tests for PCLA implementation

Many of them have been found & minimized at FP tests/user projects

^KT-59791 Fixed

compiler/testData/diagnostics/tests/inference/builderInference/manyArgsDifferentYields.kt

@@ -0,0 +1,23 @@
+// FIR_IDENTICAL
+class Controller<T> {
+    fun yield(t: T): Boolean = true
+}
+
+fun <S> generate(g: suspend Controller<S>.() -> Unit): S = TODO()
+
+interface Base
+interface Derived : Base
+
+fun foo(
+    base: Base,
+    derived: Derived,
+) {
+    val t = generate {
+        twoBooleans(yield(base), yield(derived))
+    }
+
+    // Should be Base, not just Derived
+    <!DEBUG_INFO_EXPRESSION_TYPE("Base")!>t<!>
+}
+
+fun twoBooleans(x: Boolean, y: Boolean) {}