Adding new API object to maintain state between calls to parser.
The state is incremental: all declarations of sorts and functions are valid in the next parse. The parser produces an ast-vector of assertions that are parsed in the current calls.
The following is a unit test:
```
from z3 import *
pc = ParserContext()
A = DeclareSort('A')
pc.add_sort(A)
print(pc.from_string("(declare-const x A) (declare-const y A) (assert (= x y))"))
print(pc.from_string("(declare-const z A) (assert (= x z))"))
print(parse_smt2_string("(declare-const x Int) (declare-const y Int) (assert (= x y))"))
s = Solver()
s.from_string("(declare-sort A)")
s.from_string("(declare-const x A)")
s.from_string("(declare-const y A)")
s.from_string("(assert (= x y))")
print(s.assertions())
s.from_string("(declare-const z A)")
print(s.assertions())
s.from_string("(assert (= x z))")
print(s.assertions())
```
It produces results of the form
```
[x == y]
[x == z]
[x == y]
[x == y]
[x == y]
[x == y, x == z]
```
Thus, the set of assertions returned by a parse call is just the set of assertions added.
The solver maintains state between parser calls so that declarations made in a previous call are still available when declaring the constant 'z'.
The same holds for the parser_context_from_string function: function and sort declarations either added externally or declared using SMTLIB2 command line format as strings are valid for later calls.
remove option for uzers (users who are in reality fuzzers) to toggle flat option. The legacy arithmetic solver bakes in assumptions about flat format so it isn't helpful to expose this to fuzzers, I mean uzers.
* make JS api more idiomatic
* make JS api type-safe by default
* use strings, not symbols, for results
* add toString
* add miracle sudoku example
* ints should be ints
* add error handling
* add missing Cond to Context
* fewer side-effecting getters
remaining perf bug is dealing with very large bit-widths. mod 2^n should be computed natively based on n instead of 2^n because we pre-populate an array with all values up to n. Suppose n is 10000, the array has size 10000.
TraceToFile does not correspond to the functionality of enable_trace. Z3_enable_trace tags a trace tag as input. It can be invoked multiple times with different tags. The debug tracing then shows logs with the corresponding tags.
Make it easier to add native methods for callbacks (for user propagator) #6097
The Java User propagator wrapper should define a base class with virtual methods that can be invoked from functions defined in NativeStatic.txt
The rc2bin heuristic is a hybrid of rc2 and binary maxres.
It follows the suggestion by Nina to use rc2 on large cores after a single maxres relaxation step; otherwise maxres (binary) on smaller cores. In the design space of possible hybrids, this variant chooses to always apply a single layer of maxres and then rc2 for large cores.
