pgsql: Prevent passing gmake's environment variables down through pg_re

Prevent passing gmake's environment variables down through pg_regress.

When we do "make install" to create a temp installation, we don't want
that instance of make to try to communicate with any instance of make
that might be calling us.  This is known to cause problems if the
upper make has a -jN flag, and in principle could cause problems even
without that.  Unset the relevant environment variables to prevent such
issues.

Andres Freund

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/19a08ef7d3a8cd8327289c2183f8402d6b7dade9

Modified Files
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src/test/regress/pg_regress.c |   13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)