pgsql: Make init_spin_delay() C89 compliant and change stuck spinlock r

Make init_spin_delay() C89 compliant and change stuck spinlock reporting.

The current definition of init_spin_delay (introduced recently in
48354581a) wasn't C89 compliant. It's not legal to refer to refer to
non-constant expressions, and the ptr argument was one.  This, as
reported by Tom, lead to a failure on buildfarm animal pademelon.

The pointer, especially on system systems with ASLR, isn't super helpful
anyway, though. So instead of making init_spin_delay into an inline
function, make s_lock_stuck() report the function name in addition to
file:line and change init_spin_delay() accordingly. While not a direct
replacement, the function name is likely more useful anyway (line
numbers are often hard to interpret in third party reports).

This also fixes what file/line number is reported for waits via
s_lock().

As PG_FUNCNAME_MACRO is now used outside of elog.h, move it to c.h.

Reported-By: Tom Lane
Discussion: 4369.1460435533@sss.pgh.pa.us

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/80abbeba23d466b6541cf95082a9e1f36704424e

Modified Files
--------------
src/backend/storage/buffer/bufmgr.c |  4 ++--
src/backend/storage/lmgr/lwlock.c   |  2 +-
src/backend/storage/lmgr/s_lock.c   | 18 ++++++++++--------
src/include/c.h                     | 11 +++++++++++
src/include/storage/s_lock.h        |  9 +++++----
src/include/utils/elog.h            | 12 ------------
6 files changed, 29 insertions(+), 27 deletions(-)