SI-2807 Resurrect and refine the promiscuous catch warning.

The previous incarnation didn't survive 4fb3473.

This version can be cleared by using a typed pattern: `catch { case _: Throwable => }`.

This is motivated by the recent appearance of such a catch in `util.Try`, and by battle
scars left by one too many processes bravely but stupidly catching and logging OutOfMemoryErrors.

-Y status has been skipped: this warning is enabled by default and can only be silenced
with use of a typed pattern.

1 files changed, 19 insertions, 0 deletions

diff --git a/test/files/neg/catch-all.scala b/test/files/neg/catch-all.scala
new file mode 100644
index 0000000000..35a6d7af91
--- /dev/null
+++ b/test/files/neg/catch-all.scala
@@ -0,0 +1,19 @@
+object CatchAll {
+	try { "warn" } catch { case _ => }
+
+	try { "warn" } catch { case x => }
+
+	try { "warn" } catch { case _: RuntimeException => ; case x => }
+
+	try { "okay" } catch { case _: Throwable => }
+
+	try { "okay" } catch { case _: Exception => }
+
+	try { "okay" } catch { case okay: Throwable => }
+
+	try { "okay" } catch { case okay: Exception => }
+
+	try { "okay" } catch { case _ if "".isEmpty => }
+
+	"okay" match { case _ => "" }
+}