pgsql: Fix pg_upgrade, broken by the xlogid/segno -> 64-bit int refacto

Fix pg_upgrade, broken by the xlogid/segno -> 64-bit int refactoring.

The xlogid + segno representation of a particular WAL segment doesn't make
much sense in pg_resetxlog anymore, now that we don't use that anywhere
else. Use the WAL filename instead, since that's a convenient way to name a
particular WAL segment.

I did this partially for pg_resetxlog in the original xlogid/segno -> uint64
patch, but I neglected pg_upgrade and the docs. This should now be more
complete.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/038f3a05092365eca070bdc588554520dfd5ffb9

Modified Files
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contrib/pg_upgrade/controldata.c | 52 +++++++++++++++++++++++++++++------
contrib/pg_upgrade/pg_upgrade.c | 6 +---
contrib/pg_upgrade/pg_upgrade.h | 3 +-
doc/src/sgml/ref/pg_resetxlog.sgml | 7 +----
src/bin/pg_resetxlog/pg_resetxlog.c | 27 +++---------------
5 files changed, 51 insertions(+), 44 deletions(-)