Previously the computation of the total test duration, measured in
microseconds, accidentally overflowed due to accidentally using signed
32bit arithmetic. As the only consequence is that pg_test_timing
invocations with such, overly large, durations never finished the
practical consequences of this bug are minor.
Pointed out by Coverity.
Backpatch to 9.2 where pg_test_timing was added.
Prominent binaries already had this metadata. A handful of minor
binaries, such as pg_regress.exe, still lack it; efforts to eliminate
such exceptions are welcome.
Michael Paquier, reviewed by MauMau.
