[lldb] Fix member access in GetExpressionPath
This change fixes two issues in ValueObject::GetExpressionPath method:
1. Accessing members of struct references used to produce expression
paths such as "str.&str.member" (instead of the expected
"str.member"). This is fixed by assigning the flag tha the child
value is a dereference when calling Dereference() on references
and adjusting logic in expression path creation.
2. If the parent of member access is dereference, the produced
expression path was "*(ptr).member". This is incorrect, since it
dereferences the member instead of the pointer. This is fixed by
wrapping dereference expression into parenthesis, resulting with
"(*(ptr)).member".
Reviewed By: werat, clayborg
Differential Revision: https://reviews.llvm.org/D132734