(proof-new) Update Theory interface for proof-new (#4648)

This includes 4 changes:

Theory constructor takes a ProofNodeManager,
Theory::explain returns a TrustNode (of kind PROP_EXP),
Theory::expandDefinitions returns a TrustNode (of kind REWRITE),
Theory::ppRewrite returns a TrustNode (of kind REWRITE).
These are all currently planned updates to the interface of Theory.
This PR also connects some of the existing proof rule checkers into the proof checker, if one is provided to the constructor. It updates TheoryEngine and other places to process TrustNode in trivial ways (converting them into Node). These calls will later be updated as needed for proof support.

This PR is also contingent on the performance tests for proof-new on SMT-LIB.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/theory/theory_preprocessor.cpp b/src/theory/theory_preprocessor.cpp
index d5a66ef9b..b12916b7d 100644
--- a/src/theory/theory_preprocessor.cpp
+++ b/src/theory/theory_preprocessor.cpp
@@ -201,7 +201,8 @@ Node TheoryPreprocessor::ppTheoryRewrite(TNode term)
   unsigned nc = term.getNumChildren();
   if (nc == 0)
   {
-    return d_engine.theoryOf(term)->ppRewrite(term);
+    TrustNode trn = d_engine.theoryOf(term)->ppRewrite(term);
+    return trn.isNull() ? Node(term) : trn.getNode();
   }
   Trace("theory-pp") << "ppTheoryRewrite { " << term << endl;
 
@@ -225,7 +226,8 @@ Node TheoryPreprocessor::ppTheoryRewrite(TNode term)
     }
     newTerm = Rewriter::rewrite(Node(newNode));
   }
-  Node newTerm2 = d_engine.theoryOf(newTerm)->ppRewrite(newTerm);
+  TrustNode trn = d_engine.theoryOf(newTerm)->ppRewrite(newTerm);
+  Node newTerm2 = trn.isNull() ? newTerm : trn.getNode();
   if (newTerm != newTerm2)
   {
     newTerm = ppTheoryRewrite(Rewriter::rewrite(newTerm2));