Unjustified optimization due to restricted struct members?

[Ties Klappe <tg.klappe@gmail.com>]

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When reading section 6.7.3.1 of the C standard (quoted below) about
the *restrict
*type qualifier, the first section talks about *ordinary identifiers*.
These are defined in section 6.2.3, and exclude members of structures.

Let D be a declaration of an ordinary identifier that provides a means of
> designating an object P as a restrict-qualified pointer to type T.


I would assume that this means that in the code excerpt below the function
*h* cannot be optimized by substituting the load of *b.p *for *10*, as the
standard does not specify what it means for a struct member to be restrict
qualified. However, the code is still optimized by gcc (but not Clang), as
can be seen here: https://godbolt.org/z/hEnKKoaae

struct bar {
int* restrict p;
int* restrict q;
};

int h(struct bar b) {
*b.p = 10;
*b.q = 11;
return *b.p;
}

Was this a deliberate choice, or does it simply follow from how restrict is
supported in gcc (and could this be considered a bug w.r.t. the standard)?