Adds result for `ModuleVariableNode::getARead` corresponding to reads
that go through (chains of) `import *`.
This required a bit of a change to _which_ module variables we define.
Previously, we only included variables that were accessed elsewhere in
the same file, but now we must ensure to also include variables that may
be accessed through `import *`.
Thanks @yoff, this leaves us with the following evaluation, which looks
very close to the one in the other fix (but with cleaner implementation)
-- both at 688k max tuples (although numbers are not exactly the same).
```
[2021-11-24 13:48:40] (14s) Tuple counts for PoorMansFunctionResolution::getSimpleMethodReferenceWithinClass#ff/2@e5f05asv after 74ms:
47493 ~3% {3} r1 = JOIN Class::Class::getAMethod_dispred#ff WITH py_Classes ON FIRST 1 OUTPUT Lhs.1, 0, Lhs.0
47335 ~0% {2} r2 = JOIN r1 WITH AstGenerated::Function_::getArg_dispred#fff ON FIRST 2 OUTPUT Rhs.2, Lhs.2
46683 ~0% {2} r3 = JOIN r2 WITH DataFlowPublic::ParameterNode::getParameter_dispred#fb_10#join_rhs ON FIRST 1 OUTPUT Rhs.1, Lhs.1
259968 ~4% {2} r4 = JOIN r3 WITH LocalSources::Cached::hasLocalSource#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1, Lhs.1
161985 ~0% {3} r5 = JOIN r4 WITH Attributes::AttrRef::accesses_dispred#bff_102#join_rhs ON FIRST 1 OUTPUT Rhs.1 'result', Lhs.1, Rhs.2
161985 ~2% {3} r6 = JOIN r5 WITH Attributes::AttrRead#class#f ON FIRST 1 OUTPUT Lhs.2, Lhs.1, Lhs.0 'result'
688766 ~0% {3} r7 = JOIN r6 WITH Function::Function::getName_dispred#ff_10#join_rhs ON FIRST 1 OUTPUT Lhs.1, Rhs.1 'func', Lhs.2 'result'
20928 ~0% {2} r8 = JOIN r7 WITH Class::Class::getAMethod_dispred#ff ON FIRST 2 OUTPUT Lhs.1 'func', Lhs.2 'result'
return r8
```
This predicate was materialised as a _big_, _cached_ relation:
```
(169s) Tuple counts for PointsTo::InterProceduralPointsTo::named_argument_transfer#ffff#join_rhs/4@38ce07 after 53.4s:
25212 ~4% {3} r1 = SCAN Function::Function::getArgByName_dispred#fff OUTPUT In.1, In.0 'arg1', In.2 'arg2'
159751200 ~0% {4} r2 = JOIN r1 WITH Flow::CallNode::getArgByName_dispred#fff_102#join_rhs ON FIRST 1 OUTPUT Rhs.1 'arg0', Lhs.1 'arg1', Lhs.2 'arg2', Rhs.2 'arg3'
return r2
```
... However it's only used in a single place (where it is immediately
joined with the points-to relation to relate the caller and argument),
none of these joins were ever larger than 2000 tuples. This made it
pretty clear that we could gain something by pushing in that points-to
join as a bit of manual magic.
However, doing so didn't actually fix anything, since the join-orderer
then decided to join `func.getArgByName(name)` with
`call.getArgByName(name)` on `name` as the first thing (which caused a
join of the same size as above).
Unbinding didn't work, since `name` would then be an unbound `string`,
so instead I factored out relating the function, parameter, and name
thereof into its own predicate. (I could also have done this with the
call, but I would expect there to be more calls than function
definitions in general.)
Overall, this resulted in going from
```
(709s)
Definitions.ql-7:PointsTo::InterProceduralPointsTo::named_argument_transfer#ffff#join_rhs ......... 53.5s
Definitions.ql-7:Instances::InstanceObject::initializer_dispred#fbf ............................... 35.3s (456 evaluations with max 136ms in Instances::InstanceObject::initializer_dispred#fbf/3@i110#0508e8)
Definitions.ql-10:DefinitionTracking::jump_to_defn_attribute#fbf .................................. 27s (100 evaluations with max 12.8s in DefinitionTracking::jump_to_defn_attribute#fbf/3@i1#fc1f7x)
Definitions.ql-7:PointsTo::PointsToInternal::pointsTo#ffff ........................................ 16.1s (681 evaluations with max 2.5s in PointsTo::PointsToInternal::pointsTo#ffff/4@i4#0508eg)
Definitions.ql-7:Constants::ConstantObjectInternal::attribute#ffff ................................ 13.4s (505 evaluations with max 50ms in Constants::ConstantObjectInternal::attribute#ffff/4@i153#0508e5)
Definitions.ql-10:DefinitionTracking::assignment_jump_to_defn_attribute#fbf ....................... 12.4s (99 evaluations with max 11.8s in DefinitionTracking::assignment_jump_to_defn_attribute#fbf/3@i2#fc1f
7z)
...
```
to
```
(668s)
Definitions.ql-7:Instances::InstanceObject::initializer_dispred#fbf ................... 35.4s (456 evaluations with max 140ms in Instances::InstanceObject::initializer_dispred#fbf/3@i110#bf4328)
Definitions.ql-10:DefinitionTracking::jump_to_defn_attribute#fbf ...................... 27.4s (100 evaluations with max 13.3s in DefinitionTracking::jump_to_defn_attribute#fbf/3@i1#679d7x)
Definitions.ql-7:PointsTo::PointsToInternal::pointsTo#ffff ............................ 16.1s (681 evaluations with max 2.5s in PointsTo::PointsToInternal::pointsTo#ffff/4@i4#bf432g)
Definitions.ql-7:Constants::ConstantObjectInternal::attribute#ffff .................... 14.4s (505 evaluations with max 51ms in Constants::ConstantObjectInternal::attribute#ffff/4@i140#bf4325)
Definitions.ql-10:DefinitionTracking::assignment_jump_to_defn_attribute#fbf ........... 12.3s (99 evaluations with max 11.7s in DefinitionTracking::assignment_jump_to_defn_attribute#fbf/3@i2#679d
7z)
...
```
