Instrumentation breakpoint

This tests that we can hit breakpoints in JavaScript on initial load (essentially tests that DevTools properly uses the Debugger.setInstrumentationBreakpoint API).

Steps

1. Open DevTools
2. Set a breakpoint in function foo in instrumentation-breakpoint.ts line 2
3. Open a new tab (optionally closing this tab) and open DevTools
4. Navigate to this page in the new tab
5. DevTools should pause on the breakpoint in function foo