Summary:
When C and C++ code handle a common struct typed value, the struct
type is handled as a `CStruct` in the C code, but as a `CppClass` in
the C++ code. On the other hand, `Fieldname.t` contains a string of
field and **the struct type**. As a result, even if a same field is
accessed in C and C++ code, the accessed fieldnames are different.
```
void callee_in_c(struct s* x) {
x->a = 3;
}
void caller_in_cpp() {
struct s x;
x.a = 5;
callee_in_c(&x);
// HERE
}
```
For example, in the above code, `caller_in_cpp` sets the field `a` as
5, then calls `callee_in_c`, which sets the field `a` as 3. However,
at `HERE`, the value of `x` in Pulse is `{a -> 5, a -> 3}`, because the two
fieldnames are addressed as different ones.
To avoid the issue, this diff loosens the fieldname comparison in
Pulse.
Reviewed By: jvillard
Differential Revision: D26000812
fbshipit-source-id: 77142ebda
Sungkeun Cho