JVM_IR: Rewrite '?.' and '?:' chains

This shortens code and avoids unnecessary boxing in some cases.

compiler/testData/codegen/bytecodeText/boxingOptimization/safeCallWithElvis.kt

@@ -1,6 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
-// TODO KT-36651 Avoid boxing in safe call / elvis chains in JVM_IR
-
 class A(val x : Int, val y : A?)
 
 fun check(a : A?) : Int {
@@ -9,4 +6,9 @@ fun check(a : A?) : Int {
 
 // 0 valueOf
 // 0 Value\s\(\)
+
+// JVM_TEMPLATES:
 // 0 ACONST_NULL
+
+// JVM_IR_TEMPLATES:
+// 1 ACONST_NULL