fix(library/blast): uninitialized variables

src/library/blast/choice_point.h

@@ -20,6 +20,7 @@ class choice_point_cell {
     MK_LEAN_RC(); // Declare m_rc counter
     void dealloc() { delete this; }
 public:
+    choice_point_cell():m_rc(0) {}
     virtual ~choice_point_cell() {}
     /** \brief Update next proof state. This method may
         perform destructive updates, choice points are not shared

src/library/blast/state.cpp

@@ -706,7 +706,7 @@ branch_extension & state::get_extension(unsigned extid) {
     lean_assert(extid < get_extension_manager().get_num_extensions());
     if (!m_branch.m_extensions[extid]) {
         /* lazy initialization */
-        branch_extension * ext = get_extension_manager().get_initial(extid)->clone();;
+        branch_extension * ext = get_extension_manager().get_initial(extid)->clone();
         ext->inc_ref();
         m_branch.m_extensions[extid] = ext;
         lean_assert(ext->get_rc() == 1);

src/library/blast/state.h

@@ -45,6 +45,7 @@ class proof_step_cell {
     MK_LEAN_RC(); // Declare m_rc counter
     void dealloc() { delete this; }
 public:
+    proof_step_cell():m_rc(0) {}
     virtual ~proof_step_cell() {}
     /** \brief When an action updates the main branch of the proof state,
         it adds a proof_step object to the proof step stack.
@@ -103,6 +104,7 @@ class branch_extension {
     MK_LEAN_RC();
     void dealloc() { delete this; }
 public:
+    branch_extension():m_rc(0) {}
     virtual ~branch_extension() {}
     /** \brief Return a copy of this object */
     virtual branch_extension * clone() = 0;