Remove warnings that dotty doesn't emit from check files.

Author: DarkDimius

tests/run/Course-2002-01.check

@@ -1,6 +1,3 @@
-Course-2002-01.scala:41: warning: method loop in object M0 does nothing other than call itself recursively
-  def loop: Int = loop;
-                  ^
 232
 667
 11

tests/run/arrays.check

@@ -1,7 +1 @@
-arrays.scala:248: warning: comparing values of types Unit and Unit using `==' will always yield true
-    check(xs(0) == u0, xs(0), u0);
-                ^
-arrays.scala:249: warning: comparing values of types Unit and Unit using `==' will always yield true
-    check(xs(1) == u1, xs(1), u1);
-                ^
 checks: 2302

tests/run/collection-stacks.check

@@ -1,4 +1,3 @@
-warning: there was one deprecation warning; re-run with -deprecation for details
 3-2-1: true
 3-2-1: true
 apply

tests/run/contrib674.check

@@ -1,3 +0,0 @@
-contrib674.scala:15: warning: a pure expression does nothing in statement position; you may be omitting necessary parentheses
-    1
-    ^

tests/run/lazy-exprs.check

@@ -1,11 +1,3 @@
-lazy-exprs.scala:38: warning: match may not be exhaustive.
-It would fail on the following input: Some((x: String forSome x not in Z1))
-    t match {
-    ^
-lazy-exprs.scala:62: warning: match may not be exhaustive.
-It would fail on the following input: Some((x: String forSome x not in LazyField))
-    t match {
-    ^
 forced <z1>
 lazy val in scrutinee: ok
 forced <z1>

tests/run/nothingTypeNoFramesNoDce.check

@@ -1 +0,0 @@
-warning: -target:jvm-1.5 is deprecated: use target for Java 1.6 or above.