Added -Xlog-implicit-conversions.

New command line option prints a message whenever the compiler
inserts an implicit conversion.  Implicit parameters are not
under consideration here, since the primary motivation is to make
it easy to inspect your code for unintentional conversions, since
they can have dramatic performance implications.

  class A {
    def f(xs: Array[Byte]) = xs.size
    def g(xs: Array[Byte]) = xs.length
  }
  % scalac -Xlog-implicit-conversions logImplicits.scala
  logImplicits.scala:2: applied implicit conversion from xs.type to ?{val size: ?} = implicit def byteArrayOps(xs: Array[Byte]): scala.collection.mutable.ArrayOps[Byte]
    def f(xs: Array[Byte]) = xs.size
                             ^

1 files changed, 1 insertions, 0 deletions

diff --git a/test/files/neg/logImplicits.flags b/test/files/neg/logImplicits.flags
new file mode 100644
index 0000000000..97e5ae94ef
--- /dev/null
+++ b/test/files/neg/logImplicits.flags
@@ -0,0 +1 @@
+-Xlog-implicit-conversions
\ No newline at end of file