Match the OOM beahvior of 1.8.5

Apparently SpiderMonkey 60 changed the behavior of OOM errors to not
exit the VM. This updates the SpiderMonkey 60 implementation to match
that behavior.
diff --git a/src/couch/priv/couch_js/60/main.cpp b/src/couch/priv/couch_js/60/main.cpp
index ecedfbd..e36bc61 100644
--- a/src/couch/priv/couch_js/60/main.cpp
+++ b/src/couch/priv/couch_js/60/main.cpp
@@ -420,6 +420,7 @@
         return 1;
 
     JS::SetWarningReporter(cx, couch_error);
+    JS::SetOutOfMemoryCallback(cx, couch_oom, NULL);
     JS_SetContextPrivate(cx, args);
     JS_SetSecurityCallbacks(cx, &security_callbacks);
 
diff --git a/src/couch/priv/couch_js/60/util.cpp b/src/couch/priv/couch_js/60/util.cpp
index 894b425..92c6cbf 100644
--- a/src/couch/priv/couch_js/60/util.cpp
+++ b/src/couch/priv/couch_js/60/util.cpp
@@ -309,6 +309,14 @@
 }
 
 
+void
+couch_oom(JSContext* cx, void* data)
+{
+    fprintf(stderr, "out of memory\n");
+    exit(1);
+}
+
+
 bool
 couch_load_funcs(JSContext* cx, JS::HandleObject obj, JSFunctionSpec* funcs)
 {
diff --git a/src/couch/priv/couch_js/60/util.h b/src/couch/priv/couch_js/60/util.h
index 45caa34..407e3e6 100644
--- a/src/couch/priv/couch_js/60/util.h
+++ b/src/couch/priv/couch_js/60/util.h
@@ -35,6 +35,7 @@
 size_t couch_readfile(const char* file, char** outbuf_p);
 void couch_print(JSContext* cx, unsigned int argc, JS::CallArgs argv);
 void couch_error(JSContext* cx, JSErrorReport* report);
+void couch_oom(JSContext* cx, void* data);
 bool couch_load_funcs(JSContext* cx, JS::HandleObject obj, JSFunctionSpec* funcs);
 
 
diff --git a/src/couch/test/eunit/couch_js_tests.erl b/src/couch/test/eunit/couch_js_tests.erl
new file mode 100644
index 0000000..d3d92a2
--- /dev/null
+++ b/src/couch/test/eunit/couch_js_tests.erl
@@ -0,0 +1,45 @@
+% Licensed under the Apache License, Version 2.0 (the "License"); you may not
+% use this file except in compliance with the License. You may obtain a copy of
+% the License at
+%
+%   http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+% License for the specific language governing permissions and limitations under
+% the License.
+
+-module(couch_js_tests).
+-include_lib("eunit/include/eunit.hrl").
+
+
+-define(FUNC, <<
+  "function(doc) {\n"
+  "  var val = \"0123456789ABCDEF\";\n"
+  "  while(true) {emit(val, val);}\n"
+  "}\n"
+>>).
+
+
+couch_js_test_() ->
+    {
+        "Test couchjs",
+        {
+            setup,
+            fun test_util:start_couch/0,
+            fun test_util:stop_couch/1,
+            [
+                fun should_exit_on_oom/0
+            ]
+        }
+    }.
+
+
+should_exit_on_oom() ->
+    Proc = couch_query_servers:get_os_process(<<"javascript">>),
+    true = couch_query_servers:proc_prompt(Proc, [<<"add_fun">>, ?FUNC]),
+    ?assertThrow(
+            {os_process_error, {exit_status, 1}},
+            couch_query_servers:proc_prompt(Proc, [<<"map_doc">>, <<"{}">>])
+        ).