[JVM] Port line number tests to stepping framework.

Allow specifying JVM and JVM_IR as well as shared expectations.

Add the method name to the step.

Discard steps in synthetic methods.

compiler/testData/debug/stepping/trait.kt

@@ -0,0 +1,41 @@
+// FILE: test.kt
+
+interface A {
+    fun foo() = 32
+
+    fun bar(): Int {
+        return foo()
+    }
+}
+
+fun box() {
+    (object : A {}).bar()
+}
+
+// The JVM backend generates non-synthetic overrides of foo and bar
+// in the object both with line number 12. That means that there will
+// be steps on line number 12 on entry and exit to both bar and foo.
+
+// TODO: Is this what we want? Should they be marked as bridges instead?
+// Doesn't look like the intellij debugger skips non-synthetic bridges?
+// There seems to be some heuristics in intellij dealing with this as
+// the stepping behavior with repeated step-into is mostly OK.
+
+// IGNORE_BACKEND: JVM_IR
+// The JVM_IR backend generates non-synthetic overrides of foo and bar
+// with no line numbers. That leads to steps on line -1 but only on
+// exit from bar and foo.
+
+// LINENUMBERS
+// test.kt:12 box
+// test.kt:12 <init>
+// test.kt:12 box
+// test.kt:12 bar
+// test.kt:7 bar
+// test.kt:12 foo
+// test.kt:4 foo
+// test.kt:12 foo
+// test.kt:7 bar
+// test.kt:12 bar
+// test.kt:12 box
+// test.kt:13 box