On `pritomrajkhowa/LoopBound`:
```
Definitions.ql-3:SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentUseUse#ff ................. 4m35s
```
specifically
```
(376s) Tuple counts for SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentUseUse#ff/2@be04e9kp after 4m58s:
388843 ~0% {4} r1 = JOIN Essa::TPhiFunction#fff_2#join_rhs WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::definesAt#ffff ON FIRST 1 OUTPUT Rhs.1, Lhs.0, Rhs.2, Rhs.3
3629812090 ~1% {7} r2 = JOIN r1 WITH SsaCompute::SsaComputeImpl::variableUse#ffff ON FIRST 1 OUTPUT Lhs.0, Rhs.2, Rhs.3, Lhs.2, Lhs.3, Lhs.1, Rhs.1 'use1'
0 ~0% {2} r3 = JOIN r2 WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentVarRefs#fffff ON FIRST 5 OUTPUT Lhs.5, Lhs.6 'use1'
0 ~0% {2} r4 = JOIN r3 WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::firstUse#ff ON FIRST 1 OUTPUT Lhs.1 'use1', Rhs.1 'use2'
897141 ~0% {2} r5 = SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentUseUseSameVar#ff UNION r4
return r5
```
Clearly we do not want to join on the variable so soon. So we unbind it
and get
```
(78s) Tuple counts for SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentUseUse#ff/2@40e0e6uv after 434ms:
3377959 ~2% {4} r1 = SCAN SsaCompute::SsaComputeImpl::variableUse#ffff OUTPUT In.0, In.2, In.3, In.1 'use1'
1026855 ~2% {4} r2 = JOIN r1 WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentVarRefs#fffff ON FIRST 3 OUTPUT Lhs.0, Rhs.3, Rhs.4, Lhs.3 'use1'
129484 ~0% {2} r3 = JOIN r2 WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::definesAt#ffff_1230#join_rhs ON FIRST 3 OUTPUT Rhs.3, Lhs.3 'use1'
0 ~0% {2} r4 = JOIN r3 WITH Essa::TPhiFunction#fff_2#join_rhs ON FIRST 1 OUTPUT Lhs.0, Lhs.1 'use1'
0 ~0% {2} r5 = JOIN r4 WITH SsaCompute::SsaComputeImpl::AdjacentUsesImpl::firstUse#ff ON FIRST 1 OUTPUT Lhs.1 'use1', Rhs.1 'use2'
897141 ~0% {2} r6 = SsaCompute::SsaComputeImpl::AdjacentUsesImpl::adjacentUseUseSameVar#ff UNION r5
return r6
```
It seems the optimiser has started getting the wrong end of the stick
whenever we write `foo.getScope() = bar.getScope()` for some expressions
`foo` and `bar`.
This lead to things like
```
(196s) Tuple counts for Definitions::ModuleVariable::global_variable_callnode#ff/2@5ab278 after 2m33s:
2952757013 ~0% {2} r1 = JOIN Definitions::ModuleVariable::global_variable_callnode#ff#shared WITH Variables::Variable::getScope_dispred#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1 'this', Lhs.1 'result'
495693 ~0% {2} r2 = JOIN r1 WITH Variables::GlobalVariable#class#f ON FIRST 1 OUTPUT Lhs.0 'this', Lhs.1 'result'
453589 ~0% {2} r3 = JOIN r2 WITH Definitions::ModuleVariable#f ON FIRST 1 OUTPUT Lhs.0 'this', Lhs.1 'result'
return r3
```
and
```
(315s) Tuple counts for Definitions::SsaSourceVariable::getAUse_dispred#ff/2@a39328 after 1m57s:
...
1785275 ~3% {2} r24 = Definitions::ModuleVariable::global_variable_callnode#ff#shared UNION Definitions::SsaSourceVariable::getAUse_dispred#ff#shared
3008614987 ~0% {2} r25 = JOIN r24 WITH Variables::Variable::getScope_dispred#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1 'this', Lhs.1 'result'
127 ~1% {2} r26 = JOIN r25 WITH Definitions::NonLocalVariable#class#f ON FIRST 1 OUTPUT Lhs.0 'this', Lhs.1 'result'
127 ~1% {2} r27 = JOIN r26 WITH Variables::LocalVariable#f ON FIRST 1 OUTPUT Lhs.0 'this', Lhs.1 'result'
...
```
(Note the timings: 2m33s and 1m57s.)
Now we have the much more reasonable
```
(38s) Tuple counts for Definitions::ModuleVariable::global_variable_callnode#ff/2@c53031 after 42ms:
453589 ~0% {2} r1 = JOIN Definitions::ModuleVariable::global_variable_callnode#ff#shared WITH Definitions::ModuleVariable::scope_as_global_variable#ff_10#join_rhs ON FIRST 1 OUTPUT Rhs.1 'this', Lhs.1 'result'
return r1
```
and
```
(46s) Tuple counts for Definitions::SsaSourceVariable::getAUse_dispred#ff/2@4b19de after 375ms:
...
```
