Fix StdVBoolImplementation to handle large vectors

[tberghammer]

Summary

Fix StdVBoolImplementation to handle large vectors

The previous implementation only read out the first element of the underlying storage array. Because of it only the first 32 (on x86) or the first 64 (on x86_64) element was displayed.

[sivachandra]

LGTM. Thanks for doing this.

examples/synthetic/gnu_libstdcpp.py

def num_children(self):
           return (finish - start) * 8 + offset
       return 0
 
     def get_child_at_index(self, index):
       if index >= self.num_children():
         return None
       byte_offset = index / 8
       bit_offset = index % 8
-      data = self.start_p.GetPointeeData()
-      bit = data.GetUnsignedInt8(lldb.SBError(), byte_offset) & (1 << bit_offset)
+      element_size = self.start_p.GetType().GetPointeeType().GetByteSize()
+      data = self.start_p.GetPointeeData(byte_offset / element_size)
+      bit = data.GetUnsignedInt8(lldb.SBError(), byte_offset % element_size) & (1 << bit_offset)
       if bit != 0:
         value_expr = "(bool)true"
       else:
         value_expr = "(bool)false"
       return self.valobj.CreateValueFromExpression("[%d]" % index, value_expr)
 
     def update(self):
       try: