[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/topLevel.kt

@@ -0,0 +1,15 @@
+// FILE: test.kt
+
+fun foo() = prop
+
+val prop = 1
+
+fun box() {
+    foo()
+}
+
+// LINENUMBERS
+// test.kt:8 box
+// test.kt:3 foo
+// test.kt:8 box
+// test.kt:9 box