Joining on variable name alone is a bad thing:
```
[2022-01-25 11:13:20] (228s) Tuple counts for Variable::Cached::access#ff#shared/3@868b54tu after 3m37s:
112554 ~0% {3} r1 = JOIN Variable::VariableReal::getNameImpl_dispred#ff WITH Variable::VariableReal::getDeclaringScopeImpl_dispred#ff ON FIRST 1 OUTPUT Lhs.1, Lhs.0 'arg2', Rhs.1 'arg1'
561015756 ~1% {3} r2 = JOIN r1 WITH Variable::variableName#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1 'arg0', Lhs.2 'arg1', Lhs.1 'arg2'
return r2
```
This change ensures that we join on name and scope simultaneously.
Updates the requirements on [clap](https://github.com/clap-rs/clap) to permit the latest version.
Apply this update in both the generator and extractor.
The idea behind optional results is that there may be instances where
each line of source code has many results and you don't want to annotate
all of them, but you still want to ensure that any annotations you do
have are correct.
This change makes that possible by exposing a new predicate
`hasOptionalResult`, which has the same signature as `hasResult`.
Results produced by `hasOptionalResult` will be matched against any
annotations, but the lack of a matching annotation will not cause a
failure.
We will use this in the inline tests for the API edge getASubclass,
because for each API path that uses getASubclass there is always a
shorter path that does not use it, and thus we can't use the normal
shortest-path matching approach that works for other API Graph tests.
Given the code
class A; end
class B < A; end
class C < A; end
You can find uses of B and C with the expression
API::getTopLevelMember("A").getASubclass()
Create a set of classes for components of regex literals,
separate from those of string literals. This allows us to special-case
components of free-spacing regexes (ones with the /x flag) to not have a
`getValueText()`.
This in turn is useful because our regex parser can't handle free-spacing
regexes, so excluding them ensures that we don't generate erroneous
ReDoS alerts.
