Branch replace-libdparse: Exclude argument body of __traits(compiles

[nordlow]

For instance

assert(!__traits(compiles, { auto _ = f(); }))

gives

Variable _ is never modified and could have been declared const or immutable.

. The developer might be interested in testing for such properties so analysis in __traits(compiles should be excluded.

[nordlow]

On second thought, I'm not sure this particular diagnostics should be excluded in __traits(compiles, ...) or not. But there might be other code constructs BODY that shouldn't be excluded __traits(compiles, BODY).