PR c++/92215 - flawed diagnostic for bit-field with non-integral type.

PR c++/92215 - flawed diagnostic for bit-field with non-integral type.

I noticed that for code like

  struct S {
    int *foo : 3;
  };

we generate nonsensical

  r.C:2:8: error: function definition does not declare parameters
      2 |   int *foo : 3;

It talks about a function because after parsing the declspecs of 'foo' we don't
see either ':' or "name :", so we think it's not a bit-field decl.  So we parse
the declarator and since a ctor-initializer begins with a ':', we try to parse
it as a function body, generating the awful diagnostic.  With this patch, we
issue:

  r.C:2:8: error: bit-field ‘foo’ has non-integral type ‘int*’
      2 |   int *foo : 3;

	* parser.c (cp_parser_member_declaration): Add a diagnostic for
	bit-fields with non-integral types.

	* g++.dg/diagnostic/bitfld4.C: New test.

From-SVN: r277991