pgsql: pg_dump: Tiny header cleanup

pg_dump: Tiny header cleanup

In commits 9c02e3a986da and 8ec0aaeae094, Nathan added a duplicate
TocEntry typedef forward declaration (plus assorted #ifdef hackery to
avoid C99 preprocessor issues) to deal with some very old untidyness
regarding DefnDumperPtr function prototype being located in pg_backup.h.
But there's no reason to have the DefnDumperPtr typedef (and the
accompanying DataDumperPtr typedef) in that file at all; they are better
placed in pg_backup_archiver.h, the internal header, because they are
only used internally. That also requires zero #ifdef hackery, so move
them there.

Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/202504042140.qo66ggw6wzsz@alvherre.pgsql

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4be6a74cfb1ef4c50740e4c2f97a3b478c16de73

Modified Files
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src/bin/pg_dump/pg_backup.h | 10 ----------
src/bin/pg_dump/pg_backup_archiver.h | 7 ++++---
2 files changed, 4 insertions(+), 13 deletions(-)