pgsql: Fix ecpg test building process to not generate *.dSYM junk on Ma

Fix ecpg test building process to not generate *.dSYM junk on Macs.

The trick is to not try to build executables directly from .c files,
but to always build the intermediate .o files.  For obscure reasons,
Darwin's version of gcc will leave debug cruft behind in the first
case but not the second.  Per complaint from Robert Haas.

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=72ba1f2c67e058755e21165ad8efcb0849abacd5

Modified Files
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src/interfaces/ecpg/test/Makefile.regress |    3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)