Remove self types check suppression usage from scaladoc.

Also remove private setting not used anymore.

Author: vigdorchik

src/compiler/scala/tools/nsc/settings/ScalaSettings.scala

@@ -171,7 +171,6 @@ trait ScalaSettings extends AbsScalaSettings
   val etaExpandKeepsStar = BooleanSetting ("-Yeta-expand-keeps-star", "Eta-expand varargs methods to T* rather than Seq[T].  This is a temporary option to ease transition.").
                                           withDeprecationMessage("This flag is scheduled for removal in 2.12. If you have a case where you need this flag then please report a bug.")
   val Yinvalidate     = StringSetting     ("-Yinvalidate", "classpath-entry", "Invalidate classpath entry before run", "")
-  val noSelfCheck     = BooleanSetting    ("-Yno-self-type-checks", "Suppress check for self-type conformance among inherited members.")
   val YvirtClasses    = false // too embryonic to even expose as a -Y //BooleanSetting    ("-Yvirtual-classes", "Support virtual classes")
   val YdisableUnreachablePrevention = BooleanSetting("-Ydisable-unreachable-prevention", "Disable the prevention of unreachable blocks in code generation.")
 

src/compiler/scala/tools/nsc/typechecker/Typers.scala

@@ -1749,7 +1749,6 @@ trait Typers extends Adaptations with Tags {
           if (!(selfType <:< parent.tpe.typeOfThis) &&
               !phase.erasedTypes &&
               !context.owner.isSynthetic &&   // don't check synthetic concrete classes for virtuals (part of DEVIRTUALIZE)
-              !settings.noSelfCheck &&  // setting to suppress this very check
               !selfType.isErroneous &&
               !parent.tpe.isErroneous)
           {

src/scaladoc/scala/tools/nsc/doc/Settings.scala

@@ -204,11 +204,6 @@ class Settings(error: String => Unit, val printMsg: String => Unit = println(_))
     "Group similar functions together (based on the @group annotation)"
   )
 
-  // Somewhere slightly before r18708 scaladoc stopped building unless the
-  // self-type check was suppressed.  I hijacked the slotted-for-removal-anyway
-  // suppress-vt-warnings option and renamed it for this purpose.
-  noSelfCheck.value = true
-
   // For improved help output.
   def scaladocSpecific = Set[Settings#Setting](
     docformat, doctitle, docfooter, docversion, docUncompilable, docsourceurl, docgenerator, docRootContent, useStupidTypes,