pgsql: Remove configure test for nonstandard variants of getpwuid_r().

Remove configure test for nonstandard variants of getpwuid_r().

We had code that supposed that some platforms might offer a nonstandard
version of getpwuid_r() with only four arguments.  However, the 5-argument
definition has been standardized at least since the Single Unix Spec v2,
which is our normal reference for what's portable across all Unix-oid
platforms.  (What's more, this wasn't the only pre-standardization version
of getpwuid_r(); my old HPUX 10.20 box has still another signature.)
So let's just get rid of the now-useless configure step.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/8883bae33b55a52105b1b58d0e42c5a6bda09627

Modified Files
--------------
config/c-library.m4           |   24 ------------------------
configure                     |   37 -------------------------------------
configure.in                  |    1 -
src/include/pg_config.h.in    |    3 ---
src/include/pg_config.h.win32 |    3 ---
src/port/thread.c             |   16 +---------------
6 files changed, 1 insertion(+), 83 deletions(-)