[JVM_IR] Improve debugging behavior of inline functions

Specifically, this commit improves the stepping behavior of the IR
backend around functions with defaults.

  - Improved line numbers in the default handler itself for better
    stepping when inlined.

  - Improved source information on default arguments

  - Improved test coverage of stepping behavior in old and IR backends.

Improves the stepping behaviour around inline methods with default
arguments. In particular, we now accurately step through the
evaluation of default arguments, but do _not_ spuriously show the exit
from the $default handler.

compiler/testData/codegen/boxInline/defaultValues/lambdaInlining/genericLambda.kt

@@ -1,3 +1,6 @@
+// Enable for dexing once we have a D8 version with a fix for
+// https://issuetracker.google.com/148661132
+// IGNORE_DEXING
 // NO_CHECK_LAMBDA_INLINING
 // FILE: 1.kt
 package test

compiler/testData/codegen/boxInline/defaultValues/lambdaInlining/simpleGeneric.kt

@@ -1,3 +1,6 @@
+// Enable for dexing once we have a D8 version with a fix for
+// https://issuetracker.google.com/148661132
+// IGNORE_DEXING
 // FILE: 1.kt
 // SKIP_INLINE_CHECK_IN: inlineFun$default
 package test