(U+52A1): Use `<-denotational@usage' instead of `<-denotational' for

(U+52A1): Use `<-denotational@usage' instead of `<-denotational' for
BUCS+52D9; apply new conventions for glyph granularity.
(BC-8C64): New character; use `<-denotational' for U+52A1.
(A-IWDSU-52D9): New abstract node.
(U+52D9): Use `<-denotational@usage' instead of `<-denotational' for
BUCS+52D9; add `<-denotational' for A-IWDSU-52D9; apply new
conventions for glyph granularity.
(U-0002D136): Add `<-denotational' for A-IWDSU-52D9.
(BUCS+52D9): Unify A2-DJT-00890.