Fix -Wparentheses warning in synthesized C++ code

[luc-tielen]

Resolves #2194. I compiled souffle twice, and ran souffle -g path.{cpp,dl} before and after on the following Datalog snippet:

.decl edge(x: symbol, y: symbol)
.decl reachable(x: symbol, y: symbol)

.input edge
.output reachable

reachable(x, y) :-
  edge(x, y).

reachable(x, y) :-
  edge(x, z),
  reachable(z, y).

And then diff shows the following:

$ diff path.cpp.old path.cpp.new
17c17
<   return (ramBitCast<RamSigned>(a[0]) < ramBitCast<RamSigned>(b[0]))|| (ramBitCast<RamSigned>(a[0]) == ramBitCast<RamSigned>(b[0])) && ((ramBitCast<RamSigned>(a[1]) < ramBitCast<RamSigned>(b[1])));
---
>   return (ramBitCast<RamSigned>(a[0]) < ramBitCast<RamSigned>(b[0]))|| ((ramBitCast<RamSigned>(a[0]) == ramBitCast<RamSigned>(b[0])) && ((ramBitCast<RamSigned>(a[1]) < ramBitCast<RamSigned>(b[1]))));
120c120
<   return (ramBitCast<RamSigned>(a[0]) < ramBitCast<RamSigned>(b[0]))|| (ramBitCast<RamSigned>(a[0]) == ramBitCast<RamSigned>(b[0])) && ((ramBitCast<RamSigned>(a[1]) < ramBitCast<RamSigned>(b[1])));
---
>   return (ramBitCast<RamSigned>(a[0]) < ramBitCast<RamSigned>(b[0]))|| ((ramBitCast<RamSigned>(a[0]) == ramBitCast<RamSigned>(b[0])) && ((ramBitCast<RamSigned>(a[1]) < ramBitCast<RamSigned>(b[1]))));

[codecov]

Codecov Report

Merging #2202 (8893fe8) into master (6c731e5) will decrease coverage by 0.06%.
The diff coverage is 83.25%.

@@            Coverage Diff             @@
##           master    #2202      +/-   ##
==========================================
- Coverage   75.58%   75.52%   -0.07%     
==========================================
  Files         452      452              
  Lines       27266    27394     +128     
==========================================
+ Hits        20609    20689      +80     
- Misses       6657     6705      +48     

Impacted Files	Coverage Δ
src/ast/analysis/typesystem/TypeSystem.h	84.33% <ø> (ø)
src/ast/analysis/typesystem/Type.cpp	45.84% <50.00%> (ø)
src/interpreter/Engine.cpp	87.42% <72.94%> (-2.55%)	⬇️
src/interpreter/Generator.cpp	94.85% <80.00%> (-1.03%)	⬇️
src/ast/analysis/typesystem/TypeSystem.cpp	74.31% <86.84%> (-0.44%)	⬇️
...ast/analysis/typesystem/TypeConstrainsAnalysis.cpp	99.31% <100.00%> (ø)
src/ast/analysis/typesystem/TypeConstraints.cpp	90.11% <100.00%> (+0.41%)	⬆️
src/ast/transform/IOAttributes.h	97.74% <100.00%> (+0.10%)	⬆️
src/ast/transform/TypeChecker.cpp	88.68% <100.00%> (ø)
src/interpreter/Node.h	98.02% <100.00%> (+0.16%)	⬆️
... and 7 more

[XiaowenHu96]

Thanks for this.