* library.make (HAVE_CS_TESTS, HAVE_VB_TESTS): Allow to be

* library.make (HAVE_CS_TESTS, HAVE_VB_TESTS): Allow to be
overriden.  Useful if the tests sourcefile is generated.
(TEST_COMPILE, BTEST_COMPILE): Allow these to be customized too.

Support enough features to build mscorlib.dll.
* library.make (core_sourcefile): New renamed from $(sourcefile).
(PLATFORM_excludes): Auto-detecting define that sees if
$(LIBRARY).$(PLATFORM)-excludes file exists.
(sourcefile): New.  Possibly-built file that removes
PLATFORM_excluded files from core_sourcefile.
(test_against, test_dep): New.  Allow the test assembly to be
built against a different library.
(test_lib): Allow makefile to override the name of the test
assembly.
(LIBRARY_INSTALL_DIR): If defined, switch to using $(INSTALL_LIB)
rather than $(gacutil).
(DISTFILES, dist-local): Use core_sourcefile.
(clean-local): Remove sourcefile if it was generated.
(test_lib, btest_lib): Depend on $(test_dep).

svn path=/trunk/mcs/; revision=29338