Fix two errors reported by gcc.

divine/legacy/common/bit_string.hh

@@ -22,7 +22,7 @@ using std::cerr; using std::endl;
 static const ulong_int_t bit_values[32] =
    {1, 2, 4, 8, 16, 32, 64, 128, 256, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14,
     1<<15, 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23, 1<<24,
-    1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30, 1<<31};
+    1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30, 1U<<31};
 
 
 //!Class for impementation of field of bits
@@ -116,11 +116,11 @@ class bit_string_t
   */
  size_int_t get_allocated_4bytes_count() const
   { return allocated; }
- 
+
  //!Returns a count of allocated bits
  size_int_t get_bit_count() const
   { return bits; }
- 
+
  //!Prints a sequence of zeros and ones representing a content
  //! to output stream `outs'.
  void DBG_print(std::ostream & outs = cerr) const
@@ -131,14 +131,14 @@ class bit_string_t
       if (get_bit(i)) outs << '1'; else outs << '0';
     outs << endl;
    }
- 
+
  //!Bitwisely adds `from' to (*this)
  void add(const bit_string_t & from)
   {
    for (size_int_t i = 0; i!= allocated; ++i)
      mem[i] = mem[i] | from.mem[i];
   }
- 
+
  //!Returns true iff (`bs1' & `bs2') != 0
  friend bool operator&(const bit_string_t & bs1, const bit_string_t & bs2)
   {
@@ -146,7 +146,7 @@ class bit_string_t
      if (bs1.mem[i] & bs2.mem[i]) return false;
    return true;
   }
- 
+
  //!Returns true iff (`bs1' | `bs2') != 0
  friend bool operator|(const bit_string_t & bs1, const bit_string_t & bs2)
   {
@@ -154,7 +154,7 @@ class bit_string_t
      if (bs1.mem[i] | bs2.mem[i]) return false;
    return true;
   }
- 
+
  //!Returns true iff (`bs1' xor `bs2') != 0
  friend bool operator^(const bit_string_t & bs1, const bit_string_t & bs2)
   {