C++ PATCH for more checking of DECL_MUTABLE_P

[Jason Merrill]

On 8/10/19 2:57 PM, Marek Polacek wrote:
> Some preparatory work before adding constinit.  mutable is only appropriate for
> FIELD_DECLs (when they're not static), but we've never made sure that we're not
> setting DECL_MUTABLE_P on a different _DECL.  I mean to use DECL_LANG_FLAG_0 in
> a VAR_DECL for DECL_DECLARED_CONSTINIT_P.
> 
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
> 
> 2019-08-10  Marek Polacek  <polacek@redhat.com>
> 
> 	* cp-tree.h (DECL_MUTABLE_P): Use FIELD_DECL_CHECK.

OK.

Jason