Fix SM60 build on Mac (#2401)

* fix: avoid segfaults, patch by @davisp

* fix: build against sm60 on mac needs extra compiler flags
diff --git a/src/couch/priv/couch_js/60/main.cpp b/src/couch/priv/couch_js/60/main.cpp
index c92cfb7..ecedfbd 100644
--- a/src/couch/priv/couch_js/60/main.cpp
+++ b/src/couch/priv/couch_js/60/main.cpp
@@ -487,8 +487,5 @@
         JS_MaybeGC(cx);
     }
 
-    JS_DestroyContext(cx);
-    JS_ShutDown();
-
     return 0;
 }
diff --git a/src/couch/rebar.config.script b/src/couch/rebar.config.script
index 2672578..a646861 100644
--- a/src/couch/rebar.config.script
+++ b/src/couch/rebar.config.script
@@ -108,6 +108,11 @@
             "/DXP_WIN /IC:\\relax\\js-60\\js\\src",
             "/LIBPATH:C:\\relax\\js-60\\js\\src mozjs-60.lib"
         };
+    {unix, darwin} when SMVsn == "60" ->
+        {
+            "-DXP_UNIX -I/usr/include/mozjs-60 -I/usr/local/include/mozjs-60 -std=c++14",
+            "-L/usr/local/lib -lmozjs-60 -lm -std=c++14 -lc++"
+        };
     {unix, _} when SMVsn == "60" ->
         {
             "-DXP_UNIX -I/usr/include/mozjs-60 -I/usr/local/include/mozjs-60 -std=c++14",