Fix for SI-5654.

More details as code comment and in the bug database.
Fixed SI-5708. Correctly compute accessibility for object members.
Tweak to deal with reflective mirror.

Stuff written during the era of "one symbol table" is
surprised to find two.
More useful crash reports.

If you can't get your hands on something which crashes
scalac - I know, I know - you can try this ready-made crasher.

  % cat test/pending/pos/t4717.scala
  trait Bounds[@specialized A] {
    // okay without `>: A`
    def x[B >: A]: Unit = new Bounds[B] {
      lazy val it = ???  // def or val okay
      it
    }
  }

  % scalac -d /tmp test/pending/pos/t4717.scala
  error:
       while compiling: test/pending/pos/t4717.scala
          during phase: specialize
       library version: version 2.10.0-20120510-134429-ce1d68ed19
      compiler version: version 2.10.0-20120510-152646-ba4dfd1e63
    reconstructed args: -d /tmp

    last tree to typer: Select(This(trait Bounds$mcZ$sp), x$mcZ$sp)
                symbol: method x$mcZ$sp in trait Bounds$mcZ$sp (flags: override <method> <specialized>)
     symbol definition: override def x$mcZ$sp[B >: Boolean](): Unit
                   tpe: [B >: Boolean]()Unit
         symbol owners: method x$mcZ$sp -> trait Bounds$mcZ$sp -> package <empty>
        context owners: value it -> anonymous class $anon -> method x$mcZ$sp -> trait Bounds$mcZ$sp -> package <empty>

  == Enclosing template or block ==

  Block(
    Assign(
      $anon.this."it "
      Apply( // def ???(): Nothing in object Predef, tree.tpe=Nothing
        scala.this."Predef"."$qmark$qmark$qmark" // def ???(): Nothing in object Predef, tree.tpe=()Nothing
        Nil
      )
    )
    $anon.this."it " // lazy private[this] var it: Nothing, tree.tpe=Nothing
  )

  == Expanded type of tree ==

  PolyType(
    typeParams = List(TypeParam(B >: Boolean))
    resultType = NullaryMethodType(
      resultType = TypeRef(TypeSymbol(final class Unit extends AnyVal))
    )
  )

  // And then the usual stack trace
Be discriminating about custom hashcodes.

If there are no primitives, use the regular boxy one.
Quieted down a developer warning.
Impl classes printed more accurately.

They're not traits.
Test cases.

Closes SI-4482, SI-4651, SI-3702.

Pending tests for SI-1832, SI-3439, SI-5091, SI-5231, SI-5265.
Merge commit 'refs/pull/526/head' into develop
Checkfile update.

Wonder if we should have a special area for high-turnover checkfiles.
A whole bunch of checkfile updates.

Wasn't me this time (I don't think!) Mr. Robot can't get
here too soon for me.
Forbid forward refs from self constructor invocations.

Prevents the wheels falling off during later compiler phases,
or, worse, during bytecode verification.

Closes SI-4098.
Test case closes SI-2435.
Removing redunant/passing tests from pending.
Use TreeInfo#isSelfConstrCall, rather than the hand-rolled version.
Merge commit 'refs/pull/527/head'; commit 'refs/pull/528/head'; commit 'refs/pull/529/head' into develop
remove boolean 'concrete' arg from resolveXXXTag
find unapply as member of a method call's result type
Remove the Plugin nature in the Scala compiler project file.
Merge remote-tracking branch 'main/master' into topic/virtpatmat-typetags