add new cabal test

testsuite/tests/ghc-regress/cabal/cabal02/Makefile

+TOP=../../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+CABAL_SETUP = $(FPTOOLS_TOP_ABS)/libraries/Cabal/cabal-setup/cabal-setup
+
+CONFIG_ARGS = --with-compiler=$(TEST_HC) --with-hc-pkg=$(GHC_PKG_DIR_ABS)/$(GHC_PKG_INPLACE_PGM)
+
+# We have 3 packages, P-1.0, P-2.0, and Q.  Q depends on P-1.0.
+# We have an executable R, that depends on P-2.0 and Q, so the resulting
+# executable will link to both P-1.0 and P-2.0.
+
+cabal02 : 
+	(cd P1 && $(CABAL_SETUP) configure $(CONFIG_ARGS))
+	(cd P1 && $(CABAL_SETUP) build)
+	(cd P1 && $(CABAL_SETUP) register --inplace --user)
+	(cd P2 && $(CABAL_SETUP) configure $(CONFIG_ARGS))
+	(cd P2 && $(CABAL_SETUP) build)
+	(cd P2 && $(CABAL_SETUP) register --inplace --user)
+	(cd Q  && $(CABAL_SETUP) configure $(CONFIG_ARGS))
+	(cd Q  && $(CABAL_SETUP) build)
+	(cd Q  && $(CABAL_SETUP) register --inplace --user)
+	(cd R  && $(CABAL_SETUP) configure $(CONFIG_ARGS))
+	(cd R  && $(CABAL_SETUP) build)
+	$(MAKE) clean
+
+clean ::
+	(cd P1 && $(CABAL_SETUP) unregister --user)
+	(cd P2 && $(CABAL_SETUP) unregister --user)
+	(cd Q  && $(CABAL_SETUP) unregister --user)
+	(cd P1 && $(CABAL_SETUP) clean)
+	(cd P2 && $(CABAL_SETUP) clean)
+	(cd Q  && $(CABAL_SETUP) clean)

testsuite/tests/ghc-regress/cabal/cabal02/P1/A.hs

+module A where
+
+a = 1 :: Int

testsuite/tests/ghc-regress/cabal/cabal02/P1/P1.cabal

+Name: P
+Version: 1.0
+Exposed-Modules: A
+Build-depends: base>=1.0, haskell98

testsuite/tests/ghc-regress/cabal/cabal02/P2/A.hs

+module A where
+
+a = 2

testsuite/tests/ghc-regress/cabal/cabal02/P2/P2.cabal

+Name: P
+Version: 2.0
+Exposed-Modules: A
+Build-depends: base>=1.0, haskell98

testsuite/tests/ghc-regress/cabal/cabal02/Q/B.hs

+module B where
+
+import A -- from package P
+
+b = a

testsuite/tests/ghc-regress/cabal/cabal02/Q/Q.cabal

+Name: Q
+Version: 1.0
+Build-depends: base>=1.0, haskell98, P==1.0
+Exposed-modules: B

testsuite/tests/ghc-regress/cabal/cabal02/R/Main.hs

+import A
+import B
+
+main = do print a; print b

testsuite/tests/ghc-regress/cabal/cabal02/R/R.cabal

+Name: R
+Version: 1.0
+Build-depends: base>=1.0, haskell98, P==2.0, Q
+
+Executable: R
+Main-is: Main.hs

testsuite/tests/ghc-regress/cabal/cabal02/all.T

+test('cabal02', skip_if_fast, run_command_ignore_output, ['$MAKE cabal02'])