pgsql: Allow make check in PL directories

Allow make check in PL directories

Also add make check-world target, and refactor pg_regress invocation
code in makefiles a bit.

Branch
------
master

Details
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http://git.postgresql.org/pg/commitdiff/2fd77060a2db814146cf1f6cf77755a4b4fd9a80

Modified Files
--------------
GNUmakefile.in | 5 ++++-
Makefile | 2 +-
src/Makefile.global.in | 16 +++++++++++++---
src/makefiles/pgxs.mk | 8 +++-----
src/pl/plperl/.gitignore | 2 ++
src/pl/plperl/GNUmakefile | 8 +++++---
src/pl/plpython/.gitignore | 2 ++
src/pl/plpython/Makefile | 13 +++++++++----
src/pl/tcl/.gitignore | 2 ++
src/pl/tcl/Makefile | 8 +++++---
src/test/regress/GNUmakefile | 17 ++++++++---------
src/test/regress/pg_regress.c | 2 +-
12 files changed, 55 insertions(+), 30 deletions(-)