pgsql: pageinspect: Improve page_header() for pages of 32kB

pageinspect: Improve page_header() for pages of 32kB

ld_upper, ld_lower, pd_special and the page size have been using
smallint as return type, which could cause those fields to return
negative values in certain cases for builds configures with a page size
of 32kB.

Bump pageinspect to 1.10.  page_header() is able to handle the correct
return type of those fields at runtime when using an older version of
the extension, with some tests are added to cover that.

Author: Quan Zongliang
Reviewed-by: Michael Paquier, Bharath Rupireddy
Discussion: https://postgr.es/m/8b8ec36e-61fe-14f9-005d-07bc85aa4eed@yeah.net

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/127404fbe28455d6e8183fa58f3b7aefeba8f909

Modified Files
--------------
contrib/pageinspect/Makefile                    |  2 +-
contrib/pageinspect/expected/oldextversions.out | 16 +++++++++++++
contrib/pageinspect/pageinspect--1.9--1.10.sql  | 21 +++++++++++++++++
contrib/pageinspect/pageinspect.control         |  2 +-
contrib/pageinspect/rawpage.c                   | 31 +++++++++++++++++++++----
contrib/pageinspect/sql/oldextversions.sql      |  6 +++++
6 files changed, 72 insertions(+), 6 deletions(-)