Add addtional tests for builder inference

compiler/testData/diagnostics/tests/inference/builderInference/constraints/violating.fir.kt

@@ -0,0 +1,33 @@
+// !LANGUAGE: +StableBuilderInference
+// WITH_RUNTIME
+
+interface A {
+    fun foo(): MutableList<String>
+}
+
+@ExperimentalStdlibApi
+fun main() {
+    buildList {
+        add(3)
+        object : A {
+            override fun foo(): MutableList<String> = this@buildList
+        }
+    }
+    buildList {
+        add(3)
+        val x: String = get(0)
+    }
+    buildList {
+        add("3")
+        val x: MutableList<Int> = this@buildList
+    }
+    buildList {
+        val y: CharSequence = ""
+        add(y)
+        val x: MutableList<String> = this@buildList
+    }
+    buildList {
+        add("")
+        val x: StringBuilder = get(0)
+    }
+}