* ldlang.h (enum section_type): Define.
(lang_output_section_statement_type): Remove loadable field. Add
sectype field.
(lang_enter_output_section_statement): Change flags parameter in
prototype to sectype.
* ldgram.y (typebits): Remove.
(sectype): New static variable.
(opt_at): Use sectype rather than typebits.
(type): Set sectype rather than typebits.
(atype): Likewise.
* ldlex.l: Recognize DSECT, COPY, INFO, and OVERLAY in
EXPRESSION mode.
* ldlang.c (lang_output_section_statement_lookup): Set sectype
field rather than loadable field.
(wild_doit): Check sectype rather than loadable.
(lang_record_phdrs): Likewise.
(lang_enter_output_section_statement): Rename flags parameter to
sectype. Set sectype field rather than loadable field. Set flags
field based on sectype.