Move magic header setting to -Y and add path setting

Author: Linyxus

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -341,7 +341,6 @@ private sealed trait XSettings:
   val Xdumpclasses: Setting[String] = StringSetting(AdvancedSetting, "Xdump-classes", "dir", "Dump the generated bytecode to .class files (useful for reflective compilation that utilizes in-memory classloaders).", "")
   val XjarCompressionLevel: Setting[Int] = IntChoiceSetting(AdvancedSetting, "Xjar-compression-level", "compression level to use when writing jar files", Deflater.DEFAULT_COMPRESSION to Deflater.BEST_COMPRESSION, Deflater.DEFAULT_COMPRESSION)
   val XkindProjector: Setting[String] = ChoiceSetting(AdvancedSetting, "Xkind-projector", "[underscores, enable, disable]", "Allow `*` as type lambda placeholder to be compatible with kind projector. When invoked as -Xkind-projector:underscores will repurpose `_` to be a type parameter placeholder, this will disable usage of underscore as a wildcard.", List("disable", "", "underscores"), "disable", legacyArgs = true)
-  val XmagicOffsetHeader: Setting[String] = StringSetting(AdvancedSetting, "Xmagic-offset-header", "header", "Specify the magic header comment that marks the start of the actual code in generated wrapper scripts. Example: -Xmagic-offset-header:///SOURCE_CODE_START", "")
 
   /** Documentation related settings */
   val XdropComments: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xdrop-docs", "Drop documentation when scanning source files.", aliases = List("-Xdrop-comments"))
@@ -444,6 +443,9 @@ private sealed trait YSettings:
   val YbestEffort: Setting[Boolean] = BooleanSetting(ForkSetting, "Ybest-effort", "Enable best-effort compilation attempting to produce betasty to the META-INF/best-effort directory, regardless of errors, as part of the pickler phase.")
   val YwithBestEffortTasty: Setting[Boolean] = BooleanSetting(ForkSetting, "Ywith-best-effort-tasty", "Allow to compile using best-effort tasty files. If such file is used, the compiler will stop after the pickler phase.")
 
+  val YmagicOffsetHeader: Setting[String] = StringSetting(AdvancedSetting, "Ymagic-offset-header", "header", "Specify the magic header comment that marks the start of the actual code in generated wrapper scripts. Example: -Ymagic-offset-header:SOURCE_CODE_START", "")
+  val YoriginalSourceHeader: Setting[String] = StringSetting(AdvancedSetting, "Yoriginal-source-header", "header", "Specify the magic header comment that marks the path of the original code in generated wrapper scripts. Example: -Ymagic-offset-header:ORIGINAL_SOURCE_CODE_PATH", "")
+
   // Experimental language features
   @deprecated(message = "This flag has no effect and will be removed in a future version.", since = "3.7.0")
   val YnoKindPolymorphism: Setting[Boolean] = BooleanSetting(ForkSetting, "Yno-kind-polymorphism", "Disable kind polymorphism. (This flag has no effect)", deprecation = Deprecation.removed())