also consider non-implicit locals when checking...

also consider non-implicit locals when checking shadowing of implicits:
closes #3453

nonImplicitSynonymInScope implements the predicate that is used in
tryImplicit's checks for shadowing of locally defined implicits

benchmarking shows the predicate does not significantly affect quick.comp+quick.lib (goes from 11min to 11min2s on my machine -- no optimisations)

review by odersky

1 files changed, 21 insertions, 0 deletions

diff --git a/test/files/neg/t3453.check b/test/files/neg/t3453.check
new file mode 100644
index 0000000000..52c948128c
--- /dev/null
+++ b/test/files/neg/t3453.check
@@ -0,0 +1,21 @@
+t3453.scala:18: error: type mismatch;
+ found   : A
+ required: B
+        new A
+        ^
+t3453.scala:36: error: type mismatch;
+ found   : A
+ required: B
+        new A
+        ^
+t3453.scala:50: error: type mismatch;
+ found   : A
+ required: B
+        new A
+        ^
+t3453.scala:64: error: type mismatch;
+ found   : A
+ required: B
+        new A
+        ^
+four errors found