pgsql: Cover brin/gin/gist/spgist ambuildempty routines in regression t

Cover brin/gin/gist/spgist ambuildempty routines in regression tests

Changing some TEMP or permanent tables to UNLOGGED is sufficient to
invoke these ambuildempty routines, which were all not uncovered by any
tests.  These changes do not otherwise affect the test suite.

Author: Amul Sul <sulamul@gmail.com>
Discussion: https://postgr.es/m/CAAJ_b95nneRCLM-=qELEdgCYSk6W_++-C+Q_t+wH3SW-hF50iw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4fb5c794e58613561f94ad5ea1197729be7791dc

Modified Files
--------------
src/test/regress/expected/brin.out   | 2 +-
src/test/regress/expected/gin.out    | 2 +-
src/test/regress/expected/gist.out   | 2 +-
src/test/regress/expected/spgist.out | 2 +-
src/test/regress/sql/brin.sql        | 2 +-
src/test/regress/sql/gin.sql         | 2 +-
src/test/regress/sql/gist.sql        | 2 +-
src/test/regress/sql/spgist.sql      | 2 +-
8 files changed, 8 insertions(+), 8 deletions(-)