[IR] More extensive LVT tests around destructuring

All tests in this commit _pass_ to document existing behavior, but
this will change in a separate commit as we reflect desired behavior
in the test expectations.

compiler/testData/debug/localVariables/destructuring/assignmentCustomComponentNsMultiline.kt

@@ -0,0 +1,49 @@
+
+// IGNORE_BACKEND_FIR: JVM_IR
+// FILE: test.kt
+class MyPair(val x: String, val y: String) {
+    operator fun component1(): String {
+        return "O"
+    }
+
+    operator fun component2(): String {
+        return "K"
+    }
+}
+
+fun box(): String {
+    val p = MyPair("X", "Y")
+    val
+            (
+        o
+            ,
+        k
+    )
+            =
+        p
+    return o + k
+}
+
+// EXPECTATIONS
+// test.kt:15 box:
+// test.kt:4 <init>: x:java.lang.String="X":java.lang.String, y:java.lang.String="Y":java.lang.String
+// test.kt:15 box:
+
+// EXPECTATIONS JVM
+// test.kt:23 box: p:MyPair=MyPair
+// test.kt:6 component1:
+// test.kt:18 box: p:MyPair=MyPair
+// test.kt:10 component2:
+// test.kt:20 box: p:MyPair=MyPair
+// test.kt:24 box: p:MyPair=MyPair, o:java.lang.String="O":java.lang.String, k:java.lang.String="K":java.lang.String
+
+// EXPECTATIONS JVM_IR
+// test.kt:23 box: p:MyPair=MyPair
+// test.kt:18 box: p:MyPair=MyPair
+// test.kt:6 component1:
+// test.kt:18 box: p:MyPair=MyPair
+// test.kt:23 box: p:MyPair=MyPair, o:java.lang.String="O":java.lang.String
+// test.kt:20 box: p:MyPair=MyPair, o:java.lang.String="O":java.lang.String
+// test.kt:10 component2:
+// test.kt:20 box: p:MyPair=MyPair, o:java.lang.String="O":java.lang.String
+// test.kt:24 box: p:MyPair=MyPair, o:java.lang.String="O":java.lang.String, k:java.lang.String="K":java.lang.String