SI-7752 Don't disambiguate type parameters of overloaded alts

These are passed through from `InferencerContextErrors#applyErrorMsg`
to `withDisambiguation` as the `locals` parameter, which is promptly
ignored. This looks to be an unintended change in 39938bcc299.

Without this patch, the enclosed test case enters a pathalogical
disambiguation session, that not only flirts with unpleasant big-O
complexities, but also flails about appending "(in method foo)"
only to find that *all* occurences of the same-named type parameter
come from some method named "foo".

    [snipping error message 40 seconds in the making]
    method foo), O(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), P(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), Q(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), R(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), S(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), T, U(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo)(in method foo), V)
     cannot be applied to (Int)
      foo((1))
SI-7624 Fix -feature warnings and build with -feature

I added a language.existential import to LazyCombiner.scala which
should not be necessary, but causes a spurious warning otherwise:

    scala/src/library/scala/collection/parallel/mutable/LazyCombiner.scala:33:
    warning: the existential type
        scala.collection.parallel.mutable.LazyCombiner[_$1,_$2,_$3] forSome {
          type _$1; type _$2; type _$3 <: scala.collection.generic.Growable[_$1] with scala.collection.generic.Sizing },
    which cannot be expressed by wildcards, should be enabled by making the implicit value scala.language.existentials visible.
    if (other.isInstanceOf[LazyCombiner[_, _, _]]) {
                       ^

I created ticket SI-7750 to track this issue.
Formatting fixes for AnyVal

The files are not regenerated here, because additional fixes will
follow in the next commit.
SI-7624 Fix -Xlint warnings in AnyVal-related code

The changes are actually pretty small:
scala.language.implicitConversions is moved around so that it is only
emitted to the source file if there is an actual implicit conversion.
The rest of the diff are mostly the new generated source files
reflecting that change.
SI-7624 Fix a few remaining -Xlint warnings ...
in various places. This includes actors, compiler (mostly some new
macro parts) continuations, partest, scaladoc, scalap.
SI-7624 Replace new{Term,Type}Name with {Term,Type}Name
SI-7624 Fix -feature warnings in scala/tools/scalap

... and move scalap.scala.tools.scalap.scalax.rules to
scalap.scala.tools.scalap.rules now that all the Monad/Functor/
Applicatve/... stuff has been removed.
Whitespace fixes in scala/tools/scalap
addresses feedback regarding new junit tests

1. don't recreate symbol table manually and just let JUnit do it
   automatically behind the scenes
2. minor changes to assertThrow's description
3. add one more test case to check that exception's subclasses
   are catched too
4. refine rethrow test to ensure that the exception wasn't swallowed
Merge pull request #2834 from retronym/ticket/7752

SI-7752 Don't disambiguate type parameters of overloaded alts
Merge pull request #2792 from ScrapCodes/partest-script-fixed

Bug fix ! , if $color_opts is unset partest script does not work.
Merge pull request #2831 from soc/SI-7624

SI-7624 Fix -feature and some -Xlint warnings
SI-7630 [Avian] Skip test run/repl-javap-outdir-funs on Avian

The test fails, because the REPL command reports that no anonfuns were
found. I have spent a considerable amount of time to figure out what's
the issue here with no success.

Skip it for now, so that we don't lose sight of the big picture.
SI-7564 [Avian] Whitespace fixes to run/tailcalls.check

Looks like the differences in the whitespace caused the test to fail
on Avian.
SI-7716 Exclude patmat synthetics from bounds checking

Consider this pattern match translation, that occurs *before* refchecks:

    scala> val e: java.lang.Enum[_] = java.util.concurrent.TimeUnit.SECONDS

    scala> e match { case x => x }
    <console>:9: error: type arguments [_$1] do not conform to class Enum's type parameter bounds [E <: Enum[E]]
                  e match { case x => x }
                  ^
    [[syntax trees at end of                 refchecks]] // <console>
    package $line5 {
              case <synthetic> val x1: Enum[_$1] = $line3.$read.$iw.$iw.e;
              case4(){
                matchEnd3(x1)
              };
              matchEnd3(x: Enum[_$1]){
                x
              }

RefChecks turns a blind eye to the non-conformant type `Enum[_$1]` in
the label defs because of `65340ed4ad2e`. (Incidentally, that is far
too broad, as I've noted in SI-7756.)

This commit extends this exception to cover the synthetic ValDef `x1`.

Commit log watchers might notice the similarities to SI-7694.
SI-7757 disallow constructor annotations on traits

Previously it was possible to define constructor annotations on traits
with really weird side-effects (parser lost the body of the trait). Now
constructor annotations on traits will cause appropriate syntax errors.
SI-7757 add additional test case with annotation on the next line
SI-7756 Uncripple refchecks in case bodies

In 65340ed4ad2e, parts of RefChecks were disabled when
we traversed into the results of the new pattern matcher.
Similar logic existed for the old pattern matcher, but in
that case the Match / CaseDef nodes still existed in the tree.

The new approach was too broad: important checks no longer
scrutinized the body of cases.

This commit turns the checks back on when it finds the remnants
of a case body, which appears as an application to a label def.
Merge pull request #2814 from xeno-by/topic/auto-duplicate-expansions

[nomaster] macro expansions are now auto-duplicated
SI-6507 do not call .toString on REPL results when :silent is on.

Member handlers used to always call .toString on REPL results, even when
:silent was on, which could force evaluation or cause unwanted side
effects.

This forwards the current value of `printResults` to the member
handlers (through Request) for them to decide what to do when the
results must not be printed.

2 handlers now do not return any extraction code when silent:
 - ValHandler, so that it doesn't call toString on the val
 - Assign, so that it doesn't call toString on the right-hand side
   of the assignement.