Find query_source_location using lazy Enumerator

This way, we only need to filter the backtrace up to the first non-noise
stack frame.

This also updates noise to be able to deal with being passed a lazy
enum. We don't need this anywhere, but it seemed better for this to be
consistent.

activerecord/lib/active_record/log_subscriber.rb

@@ -110,7 +110,7 @@ module ActiveRecord
       end
 
       def extract_query_source_location(locations)
-        backtrace_cleaner.clean(locations).first
+        backtrace_cleaner.clean(locations.lazy).first
       end
   end
 end

activesupport/lib/active_support/backtrace_cleaner.rb

@@ -122,7 +122,11 @@ module ActiveSupport
       end
 
       def noise(backtrace)
-        backtrace - silence(backtrace)
+        backtrace.select do |line|
+          @silencers.any? do |s|
+            s.call(line)
+          end
+        end
       end
   end
 end

railties/test/backtrace_cleaner_test.rb

@@ -17,6 +17,16 @@ class BacktraceCleanerTest < ActiveSupport::TestCase
     assert_equal 1, result.length
   end
 
+  test "can filter for noise" do
+    backtrace = [ "(irb):1",
+                  "/Path/to/rails/railties/lib/rails/commands/console.rb:77:in `start'",
+                  "bin/rails:4:in `<main>'" ]
+    result = @cleaner.clean(backtrace, :noise)
+    assert_equal "/Path/to/rails/railties/lib/rails/commands/console.rb:77:in `start'", result[0]
+    assert_equal "bin/rails:4:in `<main>'", result[1]
+    assert_equal 2, result.length
+  end
+
   test "should omit ActionView template methods names" do
     method_name = ActionView::Template.new(nil, "app/views/application/index.html.erb", nil, locals: []).send :method_name
     backtrace = [ "app/views/application/index.html.erb:4:in `block in #{method_name}'"]