SI-9415 Turn on SAM by default

Initial work to change settings and test by Svyatoslav Ilinskiy
Thanks!

To avoid cycles during overload resolution (which showed up
during bootstrapping), and to improve performance, I've guarded
the detection of SAM types in `isCompatible` to cases when the
LHS is potentially compatible.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index c6c9545391..807e0cc72f 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -262,7 +262,7 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
       else {
         // Phase travel necessary. For example, nullary methods (getter of an abstract val) get an
         // empty parameter list in later phases and would therefore be picked as SAM.
-        val samSym = exitingPickler(definitions.findSam(classSym.tpe))
+        val samSym = exitingPickler(definitions.samOf(classSym.tpe))
         if (samSym == NoSymbol) None
         else Some(samSym.javaSimpleName.toString + methodSymToDescriptor(samSym))
       }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 684cf788a4..84cf3c6475 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -295,7 +295,7 @@ trait Infer extends Checkable {
         && !isByNameParamType(tp)
         && isCompatible(tp, dropByName(pt))
       )
-      def isCompatibleSam(tp: Type, pt: Type): Boolean = {
+      def isCompatibleSam(tp: Type, pt: Type): Boolean = (definitions.isFunctionType(tp) || tp.isInstanceOf[MethodType] || tp.isInstanceOf[PolyType]) &&  {
         val samFun = typer.samToFunctionType(pt)
         (samFun ne NoType) && isCompatible(tp, samFun)
       }