fix(cil2smt.ml): remove ssa visitor(bug)
fix(cil2smt.ml): correct variable numbering
feat(cil2smt.ml): encode array expression
fix(test/test6.c): change test, add int
fix(cil2smt2/test/test5.c): add sincostbl
fix(cil2smt2/basic.ml): increase precision in formatting float num
refactor(cil2smt2): move global vars upfront; clean up
feat(cil2smt2): add skeletal for call handler
feat(cil2smt2): filter out certain functions from translation

 - main, get_low_nbit
feat(cil2smt2): int variable ``x`` gets |sin(pi * x)| <= eps