[JVM+IR] Unify new debugger tests expectations

This commit unifies the expectation format between the stepping and
LVT tests in the new debugging test harness.

Furthermore, it introduces a compression of runs of locations without
linenumbers. These default to showing as bytecode offsets from
previous line number, which overspecifies the tests: the bytecodes
chosen should not be constrained by a debugging step test.

compiler/testData/debug/localVariables/jvmOverloads.kt

@@ -10,10 +10,8 @@ fun box() {
 }
 
 // LOCAL VARIABLES
-// TestKt:9:
-// C:3:
-// TestKt:9:
-// C:4:
-// C:5: firstParam:int=4:int, secondParam:java.lang.String="":java.lang.String
-// C:4:
-// TestKt:10:
+// test.kt:9 box:
+// test.kt:3 <init>:
+// test.kt:9 box:
+// test.kt:5 foo: firstParam:int=4:int, secondParam:java.lang.String="":java.lang.String
+// test.kt:10 box: