hover and clicking on a function jumps back to the previous function

[jmesserly]

After the fix to #32083, we are able to hover over most function/method calls, however, there are two issues:

• clicking on it takes you to the previous function. This is somewhat intentional, as we don't want to provide a source mapping for the top-level startup code in the module. But there may be a way to jump to the function definition itself. Needs investigation
• top-level functions show up as "anonymous" rather than inferring the name from the property they're assigned to

CC @vsmenon