Fix use-after-free due to destruction order (#2739)

A test for PR #2737 was failing even though the PR only added dead code.
This PR fixes the issue by fixing two use-after-free bugs:

- `ResolutionBitVectorProof` has a `Context` and a
`std::unique_ptr<BVSatProof>` member. The `BVSatProof` depends on the
`Context` and tries to access it (indirectly) in its constructor but
because the context was declared after the proof, the context was
destroyed before the proof, leading to a use-after-free in a method
called from the proof's destructor. This commit reorders the two
members.
- `TLazyBitblaster` was destroyed before the `LFSCCnfProof` in
`BitVectorProof` because `SmtEngine`'s destructor first destroyed the
theory engine and then the proof manager. This lead to a use-after-free
because `LFSCCnfProof` was using the `d_nullContext` of
`TLazyBitblaster`, which got indirectly accessed in `LFSCCnfProof`'s
destructor. This commit moves the destruction of `ProofManager` above
the destruction of the theory engine.

The issues were likely introduced by #2599. They went undetected because
our nightlies' ASAN check does not use proofs due to known memory leaks
in the proof module of CVC4.

I have tested this PR up to regression level 2 with ASAN with leak
detection disabled.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/proof/resolution_bitvector_proof.h b/src/proof/resolution_bitvector_proof.h
index a54d72d3f..ccb288f6e 100644
--- a/src/proof/resolution_bitvector_proof.h
+++ b/src/proof/resolution_bitvector_proof.h
@@ -98,6 +98,8 @@ class ResolutionBitVectorProof : public BitVectorProof
   void initCnfProof(prop::CnfStream* cnfStream, context::Context* cnf) override;
 
  protected:
+  context::Context d_fakeContext;
+
   // The CNF formula that results from bit-blasting will need a proof.
   // This is that proof.
   std::unique_ptr<BVSatProof> d_resolutionProof;
@@ -105,7 +107,6 @@ class ResolutionBitVectorProof : public BitVectorProof
   bool d_isAssumptionConflict;
 
   theory::TheoryId getTheoryId() override;
-  context::Context d_fakeContext;
 };
 
 class LFSCBitVectorProof : public ResolutionBitVectorProof