JVM_IR: Use direct field access instead of calling certain accessors.

Final default properties accessors that access a backing field
on the same class can be replaced by direct field use.

Perform the optimization late in the pipeline to allow lowerings
to expose more opportunities for optimizations.

compiler/testData/codegen/bytecodeText/accessorForOverridenVal.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 package b
 
 abstract class B {

compiler/testData/codegen/bytecodeText/constants/noInlineNonConst.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 val x = 1
 
 class A {

compiler/testData/codegen/bytecodeText/kt3845.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 class Example
 {
     var a1 = 0