pgsql: Fix definition of pg_statio_all_tables view

Fix definition of pg_statio_all_tables view

pg_statio_all_tables view appears to have a wrong grouping.  As the result
numbers of toast index blocks read and hit were multiplied to the number of
table indexes.  This commit fixes the view definition.

Backpatching this appears difficult.  We don't have a mechanism to patch a
system catalog of existing instances in minor upgrade.  We can write a
release notes instruction to do this manually.  But per discussion this is
probably not so critical bug for doing such an intrusive fix.

Reported-by: Andrei Zubkov
Discussion: https://postgr.es/m/CAPpHfdtMYkkNudLMG9G0dxX_B%3Dn5sfKzOyxxrvWYtSicaGW0Lw%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ef11051bbe96ea2d06583e4b3b9daaa02657dd42

Modified Files
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src/backend/catalog/system_views.sql | 8 ++++----
src/test/regress/expected/rules.out  | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)