upm: new upm.i JS interface file with code to call v8 garbage collector

Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/upm.i

@@ -2,3 +2,22 @@
 %include "stdint.i"
 
 %typemap(out) mraa_result_t = int;
+
+#if (SWIG_JAVASCRIPT_V8)
+%{
+	// Because there's no guarantee that v8 will ever call garbage collection,
+	// we're adding a function that will allow a user to call it manually
+	void cleanUp()
+	{
+		// Call the v8 garbage collector as long as there is memory to clean up
+		// See https://codereview.chromium.org/412163003 for this API change
+#if (SWIG_V8_VERSION < 0x032838)
+		while (!v8::V8::IdleNotification())
+#else
+		while (!v8::Isolate::GetCurrent()->IdleNotification(1000))
+#endif
+		{;}
+	}
+%}
+void cleanUp();
+#endif