pgsql: Move BufferGetBlockNumber() out of heap_page_is_all_visible()'s

Move BufferGetBlockNumber() out of heap_page_is_all_visible()'s inner loop.

In some workloads BufferGetBlockNumber() shows up in profiles due to
the sheer number of calls to it (and because it causes cache
misses). The compiler can't move it out of the loop because it's a
full extern function call...

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/0c5af0a537a2d6320eb8ef7f401401aa1f47b79e

Modified Files
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src/backend/commands/vacuumlazy.c |    3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)