Run Jasmine stack traces through sourcemaps for display.
Review Request #8325 — Created Aug. 12, 2016 and submitted
Jasmine stack trace output (shown when a test fails) is hard to debug with Babel. Fortunately, there's a useful third-party module called sourcemapped-stacktrace.js, which can take a stacktrace and apply sourcemaps. This change introduces that module and a new custom module for Jasmine that will use this for all resulting stack traces.
Ran some failing unit tests where ES6 code was involved. Saw that instead
of seeing generated JavaScript output referenced in the stack traces,
the original source filenames and lines were shown instead.