remove a few default constructors

src/ast/recfun_decl_plugin.cpp

@@ -170,8 +170,6 @@ namespace recfun {
         vector<branch>      m_branches;
 
     public:
-        case_state() : m_reg(), m_branches() {}
-        
         bool empty() const { return m_branches.empty(); }
 
         branch pop_branch() {

src/ast/seq_decl_plugin.h

@@ -446,7 +446,7 @@ public:
             /*
               Default constructor of invalid info.
             */
-            info() {}
+            info() = default;
 
             /*
               Used for constructing either an invalid info that is only used to indicate uninitialized entry, or valid but unknown info value.

src/ast/sls/sls_valuation.h

@@ -33,7 +33,7 @@ namespace bv {
         unsigned nw = 0;
         unsigned mask = 0;
 
-        bvect() {}
+        bvect() = default;
         bvect(unsigned sz) : svector(sz, (unsigned)0) {}
         void set_bw(unsigned bw);