Take libraries out of test coverage

[peterschrammel]

@kroening, is this about built-ins or user-specified libraries?

[kroening]

built-ins

[peterschrammel]

The problem is a combination of the following:

1. partial inlining is done before instrumenting coverage goals
2. goto_inline tries to replace the source locations of hidden functions (i.e. built-ins) (not quite -- because it seems that locations are re-introduced through remove_returns -- I haven't investigated that further)
3. instrument_cover_goals is unable to know where the inlined code came from

@kroening, is there any reason why 2. is necessary?

[kroening]

2: To hide them -- in particular, the goal is to have assertions appear in the place where the function is called.

[peterschrammel]

Ok. Then I use ID_hide (already set in goto_inline) to identify code from built-ins.