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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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=c75e1436467f32a06b5ab9d594d2a390e7f4594d

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