pgsql: Fix pg_rewind to handle relation data files in tablespacesprope

Fix pg_rewind to handle relation data files in tablespaces properly.

pg_rewind checks whether each file is a relation data file, from its path.
Previously this check logic had the bug which made pg_rewind fail to
recognize any relation data files in tablespaces. Which also caused
an assertion failure in pg_rewind.

Back-patch to 9.5 where pg_rewind was added.

Author: Takayuki Tsunakawa
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8D6C7A@G01JPEXMBYT05

Branch
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REL9_5_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/cb5c141edac595b74ab611e86f7b1cc2be12c15e

Modified Files
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src/bin/pg_rewind/filemap.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)