backport babel skip

Author: jasonLaster

src/test/mochitest/browser.ini

@@ -107,6 +107,7 @@ support-files =
 [browser_dbg-asm.js]
 [browser_dbg-async-stepping.js]
 [browser_dbg-babel.js]
+skip-if = (os == "win" && ccov) # bug 1438797
 [browser_dbg-breaking.js]
 [browser_dbg-breaking-from-console.js]
 [browser_dbg-breakpoints.js]